APPARATUSES AND RELATED METHODS FOR DETECTING MAGNETIC FLUX FIELD CHARACTERISTICS WITH A WIRELESS POWER RECEIVER

• US 20160218520A1
• Filed: 01/22/2015
• Published: 07/28/2016
• Est. Priority Date: 01/22/2015
• Status: Active Grant

• Current Assignee: Integrated Device Technology Incorporated (Renesas Electronics Corporation)
• Original Assignee: Integrated Device Technology Incorporated (Renesas Electronics Corporation)
• Inventors: Mehas, Gustavo J., Vitchev, Vladimir N.
• Granted Patent: US 10,079,508 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 50/90 involving detection or optimisation of position, e.g. alignment

Abstract

A wireless power receiver may include a receive coil configured to generate an AC power signal, at least one secondary sensing coil configured to generate a measurement signal responsive to a magnetic flux field, and control logic configured to detect at least one condition of a wireless power transfer system responsive to detecting distortion in the magnetic flux field from the at least one measurement signal received from the secondary sensing coil. A related method may include receiving with a wireless power receiver a wireless power signal for wireless power transfer from a wireless power transmitter, generating with a plurality of secondary sensing coils one or more measurement signals responsive to a magnetic flux field generated during the wireless power transfer, and detecting at least one condition of a wireless power transfer system responsive to the one or more measurement signals generated by the plurality of secondary sensing coils.

Claims

1. A wireless power enabled apparatus, comprising:

a wireless power receiver, including;

a receive coil configured to generate an AC power signal responsive to wireless power transfer from a wireless power transmitter;

at least one secondary sensing coil configured to generate a measurement signal responsive to a magnetic flux field generated during the wireless power transfer; and

control logic operably coupled with the at least one secondary sensing coil, the control logic configured to detect at least one condition of a wireless power transfer system responsive to detecting distortion in the magnetic flux field from the measurement signal received from the at least one secondary sensing coil.

2. The wireless power enabled apparatus of claim 1, wherein the at least one secondary sensing coil includes a plurality of secondary sensing coils operably coupled with the control logic.

3. The wireless power enabled apparatus of claim 2, wherein each secondary sensing coil of the plurality of secondary sensing coils is independently coupled to the control logic to provide individual measurement signals thereto.

4. The wireless power enabled apparatus of claim 2, wherein at least two secondary sensing coil of the plurality of secondary sensing coils are coupled together to a common input of the control logic.

5. The wireless power enabled apparatus of claim 4, wherein the at least two secondary sensing coils are configured to sum their respective measurement signals to provide to the common input of the control logic.

6. The wireless power enabled apparatus of claim 4, wherein the at least two secondary sensing coils are configured to subtract their respective measurement signals to provide to the common input of the control logic.

7. The wireless power enabled apparatus of claim 2, wherein the plurality of secondary sensing coils are positioned around at least one of an outside periphery and an inner area of the receive coil.

8. The wireless power enabled apparatus of claim 2, wherein the plurality of secondary sensing coils are positioned around a peripheral component of the wireless power enabled apparatus, and wherein the control logic is further configured to determine magnetic flux penetration of the peripheral component.

9. The wireless power enabled apparatus of claim 2, wherein the plurality of secondary sensing coils are positioned at locations associated with different sides of a case of the wireless power enabled apparatus, and wherein the control logic is further configured to determine magnetic flux penetration of the case and internal peripheral components of the wireless power enabled apparatus.

10. A wireless power enabled apparatus, comprising:

a wireless power receiver, including;

a receive coil;

a plurality of secondary sensing coil located in proximity of the receive coil, each secondary sensing coil configured to generate a measurement signal of a magnetic flux field generated during wireless power transfer to the receive coil; and

control logic operably coupled with the plurality of secondary sensing coils, the control logic configured to detect at least one condition of a wireless power transfer system based, at least in part, on a measured combination of inputs from the measurement signals generated by the plurality of secondary sensing coils.

11. The wireless power enabled apparatus of claim 10, wherein the plurality of secondary sensing coils include a first secondary sensing coil and a second secondary sensing coil located along a y-axis, and a third secondary sensing coil and a fourth secondary sensing coil located along an x-axis, wherein:

the first secondary sensing coil is located along the y-axis at a +Y location;

the second secondary sensing coil is located along the y-axis at a −

Y location;

the third secondary sensing coil is located along the x-axis at a +X location; and

the fourth secondary sensing coil is located along the x-axis at a −

X location.

12. The wireless power enabled apparatus of claim 10, wherein the at least one condition includes at least one of misalignment of the transmit coil and a receive coil, a self heating condition, and a presence of a foreign object within the magnetic flux field.

13. The wireless power enabled apparatus of claim 12, wherein the control logic is further configured to determine an amount of misalignment based, at least in part, on a comparison of the measured combination of inputs with a plurality of reference measurement combinations stored in memory of the control logic.

14. The wireless power enabled apparatus of claim 12, wherein the control logic is further configured to determine the presence of the foreign object based, at least in part, on a comparison of the measured combination of inputs with alignment information stored in memory of the control logic.

15. The wireless power enabled apparatus of claim 12, wherein the control logic is further configured to determine an amount of self heating, at least in part, on a comparison of the measured combination of inputs with a plurality of reference measurement combinations stored in memory of the control logic.

16. A method of detecting a condition of a wireless power transfer system, the method comprising:

receiving with a wireless power receiver a wireless power signal for wireless power transfer from a wireless power transmitter;

generating with a plurality of secondary sensing coils one or more measurement signals responsive to a magnetic flux field generated during the wireless power transfer; and

detecting at least one condition of a wireless power transfer system responsive to the one or more measurement signals generated by the plurality of secondary sensing coils.

17. The method of claim 16, wherein detecting at least one condition of a wireless power transfer system includes at least one of:

detecting misalignment of a transmit coil of a wireless power transmitter and a receive coil of the wireless power receiver; and

detecting self heating of at least a portion of a wireless power receiving apparatus that includes the wireless power receiver; and

detecting a presence of a foreign object within the magnetic flux field detected by the plurality of secondary sensing coils.

18. The method of claim 17, wherein detecting a presence of a foreign object within the magnetic flux field includes communicating information related to the self heating to the wireless power transmitter to use in its comparison against an input power.

19. The method of claim 16, wherein detecting at least one condition of a wireless power transfer system responsive to the one or more measurement signals includes:

determining self heating information from the measurement signals as they dynamically change due to misalignment; and

communicating to the wireless power transmitter a total power loss including the self heating information and power absorbed by the receive coil.

20. The method of claim 17, further comprising at least one of:

communicating a request to the wireless power transmitter to reduce a power level responsive to a detection of misalignment of the transmit coil and the receive coil;

communicating a request to the wireless power transmitter to reduce the power level responsive to a detection of the presence of the foreign object within the magnetic flux field;

communicating a request to the wireless power transmitter to reduce a power level responsive to a detection of a rapid decrease of misalignment of the transmit coil and the receive coil;

communicating a request to the wireless power transmitter to increase the power level responsive to a determination that the misalignment of the transmit coil and the receive coil has been reduced; and

communicating a request to the wireless power transmitter increase the power level responsive to a determination that the foreign object has been removed from the magnetic flux field.