Tunable wireless power architectures

• US 10,734,842 B2
• Filed: 08/31/2017
• Issued: 08/04/2020
• Est. Priority Date: 08/04/2011
• Status: Active Grant

• Current Assignee: WiTricity Corporation
• Original Assignee: WiTricity Corporation
• Inventors: Karalis, Aristeidis, Kesler, Morris P., Hall, Katherine L., Pallo, Nathan Andrew
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): Bukhari, Aqeel H
• Application Number:
  US15/691,835
• Publication Number:
  US 20180048188A1
• Time in Patent Office: 1,069 Days
• Field of Search: None
• CPC Class Codes: B60L 2240/36 Temperature of vehicle components or parts
• CPC Class Codes: B60L 53/12 Inductive energy transfer
• 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: H01F 2003/005 Magnetic cores for receiving several windings with perpendicular axes, e.g. for antennae or inductive power transfer
• 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 50/12 of the resonant type
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• 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: 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

Abstract

Described herein are improved configurations for a wireless power transfer. The parameters of components of the wireless energy transfer system are adjusted to control the power delivered to the load at the device. The power output of the source amplifier is controlled to maintain a substantially 50% duty cycle at the rectifier of the device.

Claims

1. A wireless energy receiving device for wirelessly receiving energy to drive a load, comprising:

a device resonator;

a rectifier electrically coupled to a load and to the device resonator, the rectifier comprising controllable switching elements; and

a controller coupled to the rectifier,

wherein the controller is configured to control the switching elements of the rectifier to adjust an output voltage, current, or power presented to the load; and

wherein in a first mode of operation of the system, the controller is configured so that, to approximately maintain the output voltage, current, or power presented to the load despite changes in power delivered to the device resonator by a source resonator, the controller changes a duty cycle or a phase of the switching elements of the rectifier to cause the output voltage, current, or power presented to the load to approach a target voltage demand, current demand, or power demand associated with the load.

2. The system of claim 1, wherein the controller is configured so that when power delivered to the device resonator is less than the power demand associated with the load, the controller increases the duty cycle of the switching elements of the rectifier to increase a percentage of the power delivered to the device resonator that is directed to the load.

3. The system of claim 2, wherein:

the controller is communicatively coupled to the source resonator; and

the controller is configured to transmit a control signal to the source resonator to increase an output power level of the source resonator when the duty cycle of the switching elements of the rectifier is near to or above 50% and the output voltage, current, or power presented to the load is less than the target voltage demand, target current demand, or target power demand associated with the load.

4. The system of claim 1, wherein the controller is configured so that when the power demand associated with the load is less than a maximum load power demand, the controller reduces an output power level of the rectifier by decreasing the duty cycle or the phase of the switching elements of the rectifier.

5. The system of claim 4, wherein:

the controller is communicatively coupled to the source resonator; and

the controller is configured to transmit a control signal to the source resonator to reduce an output power level of the source resonator when the duty cycle of the switching elements of the rectifier is below 40% and the output voltage, current, or power presented to the load is greater than the target voltage demand, target current demand, or target power demand associated with the load.

6. The system of claim 1, wherein the rectifier has a half-bridge topology and the controller is configured to control a switching duty cycle of the switching elements of the rectifier.

7. The system of claim 1, wherein the rectifier has a full-bridge topology and the controller is configured to control a switching phase of the switching elements of the rectifier.

8. The system of claim 1, wherein the controller is configured to adjust at least one dead time of the switching characteristics of the switching elements of the rectifier to substantially maintain zero voltage switching.

9. The system of claim 8, wherein the controller is configured to:

receive information corresponding a measurement of an output voltage and an output current of the rectifier; and

adjust the at least one dead time of the switching characteristics of the switching elements based on the information.

10. The system of claim 1, wherein the load comprises a battery.

11. The system of claim 10, wherein during a second mode of operation of the system, the system operates bidirectionally with the load driving the device resonator through the rectifier so that the device resonator generates a magnetic field, the rectifier operates as an amplifier, and the controller is configured to adjust the duty cycle of the switching elements of the rectifier such that zero voltage switching is substantially maintained.

12. The system of claim 1, further comprising an impedance matching network coupled to the device resonator, to the rectifier, and to the controller, and comprising at least one tunable element, wherein the controller is configured to adjust the impedance matching network by adjusting the at least one tunable element.

13. A wireless energy transfer system, comprising:

a first resonator;

a second resonator;

a power supply; and

a first plurality of switching elements connected to the power supply and to the first resonator;

a second plurality of switching elements connected to a first load and to the second resonator; and

a first controller connected to the first plurality of switching elements and communicatively coupled to a second controller connected to the second plurality of switching elements,

wherein in a first mode of operation of the wireless energy transfer system;

the power supply drives the first resonator through the first plurality of switching elements with an oscillating voltage signal;

the first controller is configured to adjust a duty cycle or a phase of the first plurality of switching elements so that zero voltage switching is substantially maintained; and

the first controller is configured to adjust an output power level of the oscillating voltage signal driving the first resonator in response to a change in a power demand by the first load when the first load receives power wirelessly from the first resonator, by adjusting at least one of the duty cycle of the first plurality of switching elements, the phase of the first plurality of switching elements, and a bus voltage of the first plurality of switching elements.

14. The system of claim 13, further comprising:

the second controller; and

a sensor connected to the second controller, wherein the sensor is configured to measure information about the power demand by the first load.

15. The system of claim 13, further comprising a first impedance matching network coupled to the first plurality of switching elements and to the first resonator, and comprising at least one tunable element.

16. The system of claim 13, wherein the first load comprises a battery.

17. The system of claim 16, further comprising the battery, wherein during a second mode of operation of the system:

the battery drives the second resonator through the second plurality of switching elements to cause the second resonator to generate a magnetic field;

the first resonator receives power wirelessly from the second resonator through the magnetic field generated by the second resonator; and

the second controller is configured to adjust a duty cycle of the second plurality of switching elements such that zero voltage switching is substantially maintained.

18. The system of claim 17, further comprising a second load connected to the first resonator and configured to receive power transmitted wirelessly from the second resonator to the first resonator.

19. The system of claim 17, wherein the second controller is configured to adjust the second plurality of switching elements according to a switching frequency that defines a switching period.

20. The system of claim 17, further comprising:

a first impedance matching network coupled to the first plurality of switching elements and to the first resonator, and comprising at least one tunable element; and

a second impedance matching network coupled to the second plurality of switching elements and to the second resonator, and comprising at least one tunable element.

21. The system of claim 17, further comprising an impedance matching network coupled to the second plurality of switching elements.