WIRELESS INDUCTIVE POWER TRANSFER

• US 20180123401A1
• Filed: 12/21/2017
• Published: 05/03/2018
• Est. Priority Date: 06/19/2014
• Status: Active Grant

• Current Assignee: Koninklijke Philips N.V.
• Original Assignee: Koninklijke Philips N.V.
• Inventors: JOYE, Neil Francis, VAN WAGENINGEN, Andries, ABERNETHY, Simon George, LULOFS, Klaas Jacob
• Granted Patent: US 10,734,843 B2
• Time in Patent Office: Days
• CPC Class Codes: H02J 50/10 using inductive coupling
• 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 50/80 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: H04B 5/24 Inductive coupling
• CPC Class Codes: H04B 5/263 Multiple coils at either side
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

A wireless power transfer system includes a power transmitter (201) arranged to provide a power transfer to a power receiver (205) via a power transfer signal. The power receiver (205) comprises a first mode controller (709) for transmitting a standby mode exit request to the power transmitter (201) by changing a loading of a communication inductor (209) of the power transmitter (201). The power transmitter (201) comprises a mode controller (405) which controls the power transmitter (201) to operate in a standby mode wherein a presence of the power receiver (205) is detected but no power transfer signal is generated. It furthermore comprises a detector (403) for detecting an impedance change of the communication inductor (209). The mode controller (405) is arranged to initiate a transition from the standby mode to a power transfer mode in response to the detector (403) detecting the impedance change.

Claims

1. A wireless power transfer system including a power transmitter arranged to provide a power transfer to a power receiver via a wireless inductive power transfer signal generated by the power transmitter,

wherein:

the power receiver comprises a first mode controller for transmitting a standby mode exit request to the power transmitter by changing a loading of a communication inductor of the power transmitter; and

the power transmitter comprises;

the communication inductor for communicating with the power receiver;

a second mode controller for controlling the power transmitter to operate in a standby mode wherein a presence of the power receiver is detected but no power transfer signal is generated;

a detector for detecting an impedance change of the communication inductor;

and the second mode controller is arranged to initiate a transition from the standby mode to a power transfer mode in response to the detector detecting the impedance change;

wherein the communication inductor is part of a resonance circuit and the detector is arranged to apply an excitation signal causing oscillations to the resonance circuit, and to detect the impedance change from a measurement of at least one of a communication inductor voltage and a communication inductor current;

wherein power receiver is arranged to transmit the standby mode exit request in response to receiving a power-on user input.

2. The wireless power transfer system of claim 1 wherein the communication inductor is separate from a transmitter power coil generating the power transfer signal.

3. The wireless power transfer system of claim 1 wherein the power receiver is arranged to generate the standby mode exit request to comprise control data, and the power transmitter comprises a receiver for retrieving the control data and the second mode controller is arranged to adapt the transition from the standby mode to the power transfer mode based on the control data.

4. A method of operation for a wireless power transfer system including a power transmitter arranged to provide a power transfer to a power receiver via a wireless inductive power transfer signal generated by the power transmitter,

the method comprising:

the power transmitter operating in a standby mode wherein a presence of the power receiver is detected but no power transfer signal is generated;

the power receiver transmitting a standby mode exit request to the power transmitter by changing a loading of a communication inductor of the power transmitter;

the power transmitter detecting an impedance change of the communication inductor; and

the power transmitter initiating a transition from the standby mode to a power transfer mode in response to the detection of the impedance change;

wherein the communication inductor is part of a resonance circuit, the method further comprises the power transmitter applying an excitation signal causing oscillations to the resonance circuit, and the detection of the impedance change is from a measurement of at least one of a communication inductor voltage and a communication inductor current

wherein the power receiver transmits the standby mode exit request in response to receiving a power-on user input.