METHOD FOR MANAGING CONTACTLESS POWER TRANSFER FROM A TRANSMITTER TO A RECEIVER, AND CORRESPONDING TRANSMITTER

• US 20160372934A1
• Filed: 12/08/2015
• Published: 12/22/2016
• Est. Priority Date: 06/18/2015
• Status: Active Grant

• Current Assignee: STMicroelectronics SAS (STMicroelectronics NV)
• Original Assignee: STMicroelectronics SAS (STMicroelectronics NV)
• Inventors: Cimaz, Lionel
• Granted Patent: US 9,991,722 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• 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 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge
• 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

Contactless power transfer from a transmitter to a receiver is managed. A magnetic field is generated by the transmitter from a command at a control frequency for a switching resonant circuit. The receiver communicates information to the transmitter through modulation of the magnetic field. The modulation is detected by the transmitter so as to extract the information. An adjustment of the control frequency is then made according to the received information. The modulation detection involves detecting variations in the control frequency.

Claims

1. A method for managing contactless power transfer from a transmitter to a receiver that are coupled to one another, comprising:

generating a magnetic field by the transmitter from a command at a control frequency for a switching resonant circuit,

communicating information by the receiver involving modulation of said magnetic field,

detecting said modulation by the transmitter so as to extract said information by detecting variations in the control frequency; and

adjusting said control frequency according to said received information.

2. The method according to claim 1, further comprising:

controlling the switching resonant circuit with a control signal that is internal to an oscillating loop that maintains itself at said control frequency and incorporates said switching resonant circuit,

generating the control signal as a delayed signal resulting from detection of the changes of slope of a signal that is internal to the resonant circuit, and

wherein detecting comprises determining the period of said control signal.

3. The method according to claim 2, wherein adjusting comprises adjusting the delay of said delayed signal.

4. The method according to claim 2, wherein adjusting comprises:

determining an average for said periods of the control signal,

forming a difference between the average and a target period; and

adjusting said delay according to said difference.

5. A transmitter, comprising:

a switching resonant circuit configured to be coupled to an antenna of a receiver for contactless power transfer to the receiver,

a circuit configured to manage said contactless power transfer comprising;

a generator circuit configured to generate a magnetic field from a command at a control frequency for the switching resonant circuit,

a detector circuit configured to detect modulation of the magnetic field that is representative of information communicated by the receiver for the purpose of extracting said information, and

a processing circuit configured to adjust said control frequency according to said received information,

wherein the detection circuit is further configured to detect variations in the control frequency.

6. The transmitter according to claim 5, wherein the generator circuit comprises:

an oscillating loop that maintains itself at said control frequency and incorporates said switching resonant circuit,

a slope detection module configured to detect changes of slope of a signal that is internal to the resonant circuit and to deliver an intermediate signal,

an adjustable delay circuit connected to the output of the slope detection module in order to delay the intermediate signal and to deliver a control signal for the switching resonant circuit, and

wherein the detection circuit is further configured to determine the period of said control signal.

7. The transmitter according to claim 6, wherein the processing circuit is configured to adjust the value of the delay of the delay circuit.

8. The transmitter according to claim 6, wherein the processing circuit further includes:

an averaging circuit configured to determine an average for said periods of the control signal, and

a subtracting circuit configured to form a difference between the average and a target period so as to adjust the delay value of the delay circuit according to the difference.

9. A transmitter, comprising:

a switching resonant circuit generating an oscillating signal in response to a control signal to produce a magnetic field;

a slope detection module configured to detect changes of slope of the oscillating signal, said changes in slope indicative of modulation of said magnetic field by a receiver;

a delay circuit receiving an output of the slope detection module and implementing a variable delay to change a frequency of the control signal;

a circuit configured to determine a period of the control signal, compare the determined period to a target period, and adjust the variable delay implemented by the delay circuit in response to a difference between the determined period and the target period.

10. The transmitter according to claim 9, wherein said circuit comprises an averaging circuit configured to determine an average of multiple periods of the control signal, said average compared to the target period.

11. The transmitter according to claim 9, wherein said modulation conveys data information from the receiver to the transmitter.

12. The transmitter according to claim 11, wherein the data information relates to power regulation error.

13. The transmitter according to claim 11, wherein the data information indicates whether transmitted power to the receiver is sufficient.

14. The transmitter according to claim 13, where said circuit comprises data processing circuitry configured to adjust the target period in response to said data information.

15. A method, comprising:

generating an oscillating signal in response to a control signal to produce a magnetic field from a switching resonant circuit;

detecting changes of slope of the oscillating signal, said changes in slope indicative of modulation of said magnetic field by a receiver;

generating the control signal from the detected changes of slope with a variable delay to change a frequency of the control signal;

determining a period of the control signal;

comparing the determined period to a target period; and

adjusting the variable delay in response to a difference between the determined period and the target period.

16. The method according to claim 15, further comprising determining an average of multiple periods of the control signal, wherein comparing comprised comparing said average to the target period.

17. The method according to claim 15, wherein said modulation conveys data information from the receiver to the transmitter.

18. The method according to claim 17, wherein the data information relates to power regulation error.

19. The method according to claim 17, wherein the data information indicates whether transmitted power to the receiver is sufficient.

20. The method according to claim 19, further comprising adjusting the target period in response to said data information.