Foreign object detection in wireless energy transfer systems

• US 10,686,337 B2
• Filed: 02/15/2019
• Issued: 06/16/2020
• Est. Priority Date: 10/19/2012
• Status: Active Grant

• Current Assignee: WiTricity Corporation
• Original Assignee: WiTricity Corporation
• Inventors: Roy, Arunanshu Mohan, Katz, Noam, Kurs, Andre B., Buenrostro, Christopher, Verghese, Simon, Kesler, Morris P., Hall, Katherine L., Lou, Herbert Toby
• Primary Examiner(s): Deberadinis, Robert L
• Application Number:
  US16/277,148
• Publication Number:
  US 20190181694A1
• Time in Patent Office: 487 Days
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2240/36 Temperature of vehicle components or parts
• CPC Class Codes: B60L 2250/10 by alarm
• CPC Class Codes: B60L 2270/147 electro magnetic [EMI]
• CPC Class Codes: B60L 53/124 Detection or removal of foreign bodies
• 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 53/36 by positioning the vehicle
• CPC Class Codes: B60L 53/38 specially adapted for charging by inductive energy transfer
• CPC Class Codes: B60L 53/65 involving identification of vehicles or their battery types
• CPC Class Codes: G01R 29/0814 Field measurements related to measuring influence on or from apparatus, components or humans EMC, EMI and similar testing in general G01R31/001, e.g. in ESD, EMI, EMC, EMP testing, measuring radiation leakage; detecting presence of micro- or radiowave emitters; dosimetry; testing shielding; measurements related to lightning
• CPC Class Codes: G01V 3/081 the magnetic field is produced by the objects or geological structures characterised by the method of magnetic field measurement G01R33/00
• CPC Class Codes: G01V 3/10 using induction coils
• CPC Class Codes: G01V 3/12 operating with electromagnetic waves operating with millimetre waves G01V8/005
• 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 50/50 using additional energy repeaters between transmitting devices and receiving devices
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• 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 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 30/14 : Details associated with the interoperability, e.g. vehicle recognition, authentication, identification or billing

Abstract

The disclosure features apparatus, methods, and systems for wireless power transfer that include a power source featuring at least one resonator, a power receiver featuring at least one resonator, a first detector featuring one or more loops of conductive material and configured to generate an electrical signal based on a magnetic field between the power source and the power receiver, a second detector featuring conductive material, and control electronics coupled to the first and second detectors, where during operation, the control electronics are configured to measure the electrical signal of the first detector and compare the measured electrical signal of the first detector to baseline electrical information for the first detector to determine information about whether debris is positioned between the power source and the power receiver.

Claims

1. A wireless power transfer system, comprising:

an auxiliary coil positioned in proximity to at least one of a power source and a power receiver;

a detector positioned in proximity to at least one of the power source and the power receiver, wherein the detector is configured to generate an electrical signal in response to a change in a magnetic field; and

control electronics coupled to the auxiliary coil and to the detector, wherein the control electronics are configured to;

activate the auxiliary coil to generate a magnetic field at a position of the detector;

measure an electrical signal generated by the detector in response to the magnetic field generated by the auxiliary coil; and

determine whether debris is positioned in proximity to the at least one of the power source and the power receiver based on the measured electrical signal.

2. The system of claim 1, wherein the control electronics are configured to:

activate at least one of the power source and the auxiliary coil to generate a second magnetic field at the position of the detector;

measure a second electrical signal generated by the detector in response to the second magnetic field; and

determine an extent of misalignment between the power source and the power receiver based on the second measured electrical signal.

3. The system of claim 1, further comprising:

a first amplifier connected to the power source and configured to provide a first electrical driving signal to the power source; and

a second amplifier connected to the auxiliary coil and configured to provide a second electrical driving signal to the auxiliary coil.

4. The system of claim 1, wherein the controller is configured to determine whether debris is positioned in proximity to the at least one of the power source and the power receiver by comparing the measured electrical signal to electrical baseline information.

5. The system of claim 4, wherein the electrical baseline information comprises information about an electrical signal generated by the detector when no debris is positioned in proximity to the power source and to the power receiver.

6. The system of claim 4, wherein comparing the measured electrical signal to electrical baseline information comprises determining mean and covariance matrices for the baseline information and determining whether debris is positioned in proximity to at least one of the power source and the power receiver based on the mean and covariance matrices.

7. The system of claim 6, wherein the controller is configured to calculate a likelihood value, based on the mean and covariance matrices, that debris is positioned in proximity to at least one of the power source and the power receiver.

8. The system of claim 1, wherein the detector is coupled to the power receiver.

9. The system of claim 1, wherein the detector is positioned closer to the power receiver than to the power source.

10. The system of claim 1, wherein the detector is coupled to the power source.

11. A method, comprising:

activating an auxiliary coil, separate from a power source and from a power receiver of a wireless power transfer system, to generate a magnetic field;

using a detector positioned in proximity to at least one of the power source and the power receiver to generate an electrical signal in response to a change in a magnetic field in proximity to the detector; and

determining whether debris is positioned in proximity to at least one of the power source and the power receiver based on the electrical signal.

12. The method of claim 11, wherein the electrical signal is generated by the detector in response to a change in the magnetic field generated by the auxiliary coil.

13. The method of claim 11, wherein the electrical signal is generated by the detector in response to a change in a magnetic field that is at least partially generated by the auxiliary coil.

14. The method of claim 11, further comprising:

generating a second magnetic field in proximity to the detector;

generating a second electrical signal in response to the second magnetic field; and

determining an extent of misalignment between the power source and the power receiver based on the second electrical signal.

15. The method of claim 14, further comprising activating the power source to generate the second magnetic field.

16. The method of claim 14, further comprising activating the auxiliary coil to generate the second magnetic field.

17. The method of claim 11, further comprising providing a first electrical driving signal to the power source from a first amplifier, and providing a second electrical driving signal to the auxiliary coil from a second amplifier that is different from the first amplifier.

18. The method of claim 11, further comprising comparing the measured electrical signal to electrical baseline information to determine whether debris is positioned in proximity to the at least one of the power source and the power receiver.

19. The method of claim 18, wherein the electrical baseline information comprises information about an electrical signal generated by the detector when no debris is positioned in proximity to the power source and to the power receiver.

20. The method of claim 18, further comprising comparing the measured electrical signal to electrical baseline information by determining mean and covariance matrices for the baseline information, and determining whether debris is positioned in proximity to at least one of the power source and the power receiver based on the mean and covariance matrices.

21. The method of claim 20, further comprising calculating a likelihood value, based on the mean and covariance matrices, that debris is positioned in proximity to at least one of the power source and the power receiver.

22. The method of claim 11, wherein the detector is coupled to the power receiver.

23. The method of claim 11, wherein the detector is positioned closer to the power receiver than to the power source.

24. The method of claim 11, wherein the detector is coupled to the power source.