WIRELESS INDUCTIVE POWER TRANSFER

• US 20160156232A1
• Filed: 07/01/2014
• Published: 06/02/2016
• Est. Priority Date: 07/17/2013
• Status: Active Grant

• Current Assignee: Koninklijke Philips N.V.
• Original Assignee: Koninklijke Philips N.V.
• Inventors: Joye, Neil Francis, VAN WAGENINGEN, JR., ANDRIESS, Ettes, Wilhelmus Gerardus Maria
• Granted Patent: US 10,263,470 B2
• Time in Patent Office: Days
• 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 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• 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 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge
• CPC Class Codes: H04B 5/24 Inductive coupling
• CPC Class Codes: H04B 5/72 for local intradevice communication
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

A wireless power transfer system includes a power transmitter (101) arranged to provide a power transfer to a power receiver (105) via a wireless inductive power transfer signal where the power transfer signal is provided in a power time interval of a repeating power transfer signal time frame. The time frame furthermore comprises a reduced power time interval. An apparatus (typically being the power receiver (105) or the power transmitter (101)) comprises a short range communication unit (305, 405) arranged to communicate data messages with a second entity (which is the complementary unit, i.e. either the power transmitter (101)) or the power receiver (105)) using short range communication. The short range communication has a range not exceeding 20 cm. The apparatus further comprises a synchronization unit (309, 409) arranged to synchronize the short range communication to the power transfer signal time frame such that short range communication is restricted to the reduced power time intervals. The communication may specifically be NFC communication.

Claims

1. An apparatus for a wireless power transfer system, comprising:

a power transmitter configured to provide a power transfer to a power receiver via a wireless inductive power transfer signal, the power transfer signal during a power transfer phase being provided in a power time interval of a periodically repeating power transfer signal time frame having a repetition frequency of no less than 5 Hz and no more than 200 Hz, the power transfer signal time frame comprising a reduced power time interval, a power of the power transfer signal being reduced for the reduced power time interval relative to the power time interval;

a power transfer inductor for transferring of the power transfer signal;

a communication antenna for short range communication;

a short range communication unit coupled to the communication antenna and configured to communicate data messages with a second entity being at least one of the power transmitter and the power receiver using the short range communication, the short range communication having a range not exceeding 20 cm and using a separate carrier signal than the power transfer signal; and

a synchronizer configured to synchronize the short range communication to the power transfer signal time frame such that short range communication is restricted to the reduced power time intervals.

2. The apparatus of claim 1 wherein a carrier frequency of the carrier is no less than twice a frequency of the power transfer signal.

3. The apparatus of claim 1 wherein a power level of the power transfer signal during a reduced power time interval in a first time frame is no more than 20% of a power level of the power transfer signal during a power time interval during the first time frame.

4. The apparatus of claim 1, wherein the short-range communication is a Near Field Communication, and the short range communication unit is configured to operate as an initiator initiating a short range communication link to the second entity.

5. The apparatus of claim 1, wherein the short range communication unit is configured to reply to a data message received from the second entity in the reduced power time interval in which the data message is received from the second entity.

6. The apparatus of claim 1, wherein the short range communication unit is configured to reply to a data message received from the second entity in a subsequent reduced power time interval to the reduced power time interval in which the data message is received from the second entity.

7. The apparatus of claim 1, wherein the short range communication unit is configured to perform at least a first operation prior to entering a power transfer phase, the at least first operation comprising an operation selected from:

a detection of communication capability of the second entity;

a communication collision detection;

a communication session initialization between the apparatus and the second entity;

a device activation of the second entity.

8. The apparatus of claim 1, wherein the short range communication unit is configured to repeatedly transmit an identification of the apparatus to the second entity.

9. The apparatus of claim 1, further comprising a power transfer controller configured to inhibit power transfer in response to not receiving an indication of an identity of the second entity matching an expected identification value.

10. The apparatus of claim 1, wherein the apparatus is the power transmitter.

11. The apparatus of claim 10, further comprising

a power source for providing a periodically varying power source signal, a frequency of periodic variations in the power source signal being no more than 1 kHz;

a power transfer signal generator for generating a drive signal for a power transmit inductor from the power source signal, the power transfer signal generator comprising;

a frequency converter configured to generate a frequency of the drive signal to be higher than the frequency of periodic variations in the power source signal, and

a limiter for restricting a power of the drive signal fed to the power transmit inductor to be below a threshold in the reduced power time intervals; and

a power source synchronizer for synchronizing the reduced power time intervals to periodic variations in the power source signal.

12. The apparatus of claim 11, wherein the power source synchronizer is configured to synchronize the reduced power time intervals to correspond to periodic minima of an absolute of the power source signal.

13. The apparatus of claim 10, wherein the short range communication unit is configured to perform a detection of possible communication entities that can be communicated with by short range communication, and the apparatus further comprises a power transfer controller configured to inhibit power transfer if more than one possible communication entities are detected.

14. The apparatus of claim 10, further comprising a power transfer controller configured to inhibit power transfer in response to a detection that a response message expected from the second entity is not received within a time interval.

15. The apparatus of claim 10, further comprising a power transfer controller configured to inhibit power transfer in response to a detection of an absence of a radio signal from the second entity.

16. The apparatus of claim 1, wherein the apparatus is the power receiver.

17. The apparatus of claim 16, further comprising a controller arranged to reduce a power to a load of the power receiver in response to a detection of an absence of a communication signal from the second entity.

18. The apparatus of claim 16, further comprising a user interface configured to generate a user alert in response to a detection of an absence of a communication signal from the second entity.

19. The apparatus of claim 16, wherein the short range communication unit is configured to inhibit communication link termination with the second entity in response to a detection of the power transfer signal being present.

20. The apparatus of claim 16, wherein the synchronizer is configured to determine a timing of the power transfer signal time frame in response to periodic power variations of the power transfer signal.

21. A method of operation in a wireless power transfer system, comprising:

providing, by a power transmitter, a power transfer to a power receiver via a wireless inductive power transfer signal, the power transfer signal being provided in a power time interval of a periodically repeating power transfer signal time frame having a repetition frequency of no less than 5 Hz and no more than 200 Hz, the power transfer signal time frame comprising a reduced power time interval, a power of the power transfer signal being reduced for the reduced time interval relative to the power time interval;

communicating data messages with a second entity being at least one of the power transmitter and the power receiver using short range communication based on a separate carrier signal than the power transfer signal and using a communication antenna different from a power transfer inductor for transferring of the power transfer signal, the short range communication having a range not exceeding 20 cm; and

synchronizing the short range communication to the power transfer signal time frame such that short range communication is restricted to the reduced power time intervals.