Wireless power transfer system

Patent metadata

Field	Value
Publication number	US-2020395793-A1
Application number	US-201916971389-A
Country	US
Kind code	A1
Filing date	Feb 12, 2019
Priority date	Feb 20, 2018
Publication date	Dec 17, 2020
Grant date	—

Abstract

A power transmitter (101) for a wireless power transfer system comprises a transmitter coil (103) and a driver (201) generates a drive signal) for the transmitter coil (103) employing a repeating time frame with a power transfer time interval and a reduced power time interval during which a power level of the power transfer signal is reduced. A driver (201) generates a drive signal for the transmitter coil (103) to generate the power transfer signal. A communicator (205) receives messages from the power receiver (105) and an adapter (213) adapts a timing property of the reduced power time interval in response to at least a first message received from the power receiver (105). A synchronizer (206) for synchronizing a foreign object detection and the generation of a test signal to occur during the reduced power time interval. The operation may typically be a foreign object detection or communication, and the timing property may e.g. be a duration of the reduced power time interval.

First claim

1 . A power transmitter comprising:
a transmitter coil,
wherein the transmitter coil is arranged to generate a power transfer signal,
wherein the power transfer signal uses a repeating time frame during a power transfer phase,
wherein the repeating time frame is a least one power transfer time interval and a reduced power time interval,
wherein a power level of the power transfer signal is reduced during the reduced time interval;
a driver, wherein the driver is arranged to generate a drive signal for the transmitter coil; a first communicator, wherein the first communicator is arranged to receive messages from a power receiver; an adapter, wherein the adapter is arranged to adapt a timing property of the reduced power time interval in response to at least one first message received from the power receiver; a synchronizer, wherein the synchronizer is arranged to synchronize an operation of the power transmitter such that the operation occurs during the reduced power time interval; a test coil, wherein the test coil is arranged to generate an electromagnetic test signal; a test generator, wherein the test generator is arranged to generate a test drive signal for the test coil; and a foreign object detector, wherein the foreign object detector is arranged to perform a foreign object detection test in response to a measured parameter of the test drive signal during the reduced power time interval; wherein the synchronizer is arranged to synchronize the test generator such that the electromagnetic test signal is provided during the reduced power time interval.

2 . The power transmitter of claim 1 , wherein the timing property is a duration of the reduced power time interval.

3 . The power transmitter of claim 1 , wherein the timing property is a duration between reduced power time intervals of consecutive repeating time frames.

4 . The power transmitter of claim 1 ,
wherein the first communicator is arranged to transmit messages to the power receiver, wherein the power transmitter is arranged to transmit a second message to the power receiver prior to receiving the first message, wherein the second message indicates at least one of a duration of the reduced power time interval and a duration between reduced power time intervals of consecutive repeating time frames.

5 . The power transmitter of claim 1 ,
wherein the first message is a request message, wherein the request message indicates of a requested value for the timing property, wherein the power transmitter is arranged to accept or reject the requested value.

6 . The power transmitter of claim 1 ,
wherein the adapter is arranged to determine the timing property during an initialization phase, wherein the initialization phase occurs prior to the power transfer phase.

7 . The power transmitter of claim 1 , wherein the adapter is arranged to dynamically adapt the timing property during the power transfer phase in response to a plurality of messages received from the power receiver during the power transfer phase.

8 . The power transmitter of claim 1 , wherein the first communicator is arranged to synchronize communication with the power receiver such that the communication occurs during the reduced power time intervals.

9 . A wireless power transfer system comprising the power transmitter of claim 1 , further comprising the power receiver, the power receiver comprising:
a second communicator, wherein the second communicator is arranged to communicate with the power transmitter; a request controller,
wherein the second communicator is arranged to communicate for transmitting the first message to the power transmitter,
wherein the first message comprises a request for a requested value of the timing property;
a response controller,
wherein the response controller is arranged to receive a request response from the power transmitter,
wherein response controller is arranged to determine the timing property in response to the request response,
wherein the request response is indicative of whether the requested value has been accepted by the power transmitter; and
a load controller, wherein the load controller is arranged to adapt a loading of the power transfer signal such that the loading is reduced during the reduced power time intervals.

10 . The wireless power transfer system of claim 9 ,
wherein the request controller is arranged to request a timing property constraint from the power transmitter, wherein the response controller is arranged to receive a timing property constraint indicator from the power transmitter, wherein the request controller is arranged to determine the requested value of the timing property in response to the timing property constraint.

11 . The wireless power transfer system of claim 9 ,
wherein the timing property is a duration of the reduced power time interval, wherein the request controller is arranged to determine the requested value of the timing property subject to a maximum duration, wherein the adapter is arranged to determine a value for the timing property in response to a minimum duration.

12 . The wireless power transfer system of claim 9 ,
wherein the timing property is a duration between the reduced power transfer time of sequential repeating time frames, wherein the request controller is arranged to determine the requested value of the timing property subject to a minimum duration, wherein the adapter is arranged to determine a value for the timing property in response to a maximum duration.

13 . A method of operation for a power transmitter comprising:
generating a power transfer signal,
wherein the power transfer signal uses a repeating time frame during a power transfer phase,
wherein the repeating time frame comprises at least one power transfer time interval and a reduced power time interval,
wherein a power level of the power transfer signal is reduced during the reduced time interval;
generating a drive signal for the transmitter coil; receiving messages from a power receiver; adapting a timing property of the reduced power time interval in response to at least one first message received from the power receiver; synchronizing an operation of the power transmitter such that the operation occurs during the reduced power time interval; generating a test drive signal for a test coil, wherein the test generator is arranged to generate an electromagnetic test signal; and performing a foreign object detection test in response to a measured parameter for the test drive signal during the reduced power time interval; wherein the synchronizing comprises synchronizing the test drive signal such that the electromagnetic test signal is provided during the reduced power time interval.

14 . A method of operation for a wireless power transfer system wherein the power transfer system comprises and a power transmitter a power receiver the method comprising:
generating a power transfer signal using the power transmitter,
wherein the power transfer signal uses a repeating time frame during a power transfer phase,
wherein the repeating time frame comprises at least one power transfer time interval and a reduced power time interval,
wherein a power level of the power transfer signal is reduced;
generating a drive signal for using transmitter coil of the power transmitter to generate the power transfer signal; receiving messages from the power receiver by the power transmitter; adapting, using the power transmitter, a timing property of the reduced power time interval in response to at least one first message received from the power receiver; and synchronizing,

Assignees

• Koninklijke Philips Nv

Inventors

• Ettes Wilhelmus Gerardus Maria
• Van Wageningen Andries

Classifications

• H02J7/64

  against overvoltage · CPC title

• H02J50/10 Primary

  using inductive coupling · CPC title

• H02J50/60 Primary

  responsive to the presence of foreign objects, e.g. detection of living beings · CPC title

• H02J50/12

  of the resonant type · CPC title

• H02J50/70

  involving the reduction of electric, magnetic or electromagnetic leakage fields · CPC title