SYSTEM AND METHOD FOR POWER TRANSFER

• US 20170237296A1
• Filed: 08/12/2015
• Published: 08/17/2017
• Est. Priority Date: 08/12/2014
• Status: Active Grant

• Current Assignee: PowerbyProxi Limited (Apple Inc.)
• Original Assignee: PowerbyProxi Limited (Apple Inc.)
• Inventors: KEITH, Aaron Rex, KUMAR, Arunim, ZENG, Junbo, HARPHAM, Lewis Freeth, MARSON, Paul David, VOCKE, Sander, WANG, Ya-Ting
• Granted Patent: US 10,601,251 B2
• Time in Patent Office: Days
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• 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 7/0042 characterised by the mechanical construction
• CPC Class Codes: H02J 7/00714 in response to battery charging or discharging current

Abstract

A system for inductive power transfer that may selectively transmit power in a plurality of modes based on characteristics of a power receiver and determine which transmitter coils to drive based on received signal strength information. The inductive power transfer transmitter may detect characteristics of the power receiver in order to control the mode of the power transfer and selectively control which transmitter coils are driven based on signal strength information received from a power receiver. The power transmitter may have slugs formed of a magnetically permeable material within common coil winding openings and the transmitter coils may consists of a plurality of parallel windings.

Claims

1-106. -106. (canceled)

107. A system for power transfer comprising a power transmitter and at least one power receiver, the power transmitter having one or more transmitter coils which can be selectively caused to transmit a power signal to the power receiver in one of a plurality of modes under control of a controller to a receiver coil of the at least one power receiver,

wherein the controller is configured to detect characteristics of the power receiver in order to control the mode of the power transfer, and

wherein the power signal uses electromagnetic induction, and the characteristics of the power receiver are detected using modulation of the power signal.

108. A system according to claim 107, wherein the characteristics of the power receiver are communicated from the receiver to the transmitter by a data packet modulated onto the power signal.

109. A system according to claim 107, wherein in a first mode the transmitter responds to power flow control communication from the receiver to control power flow by adjusting the amount of power being transmitted, and in a second mode the receiver controls the power flow by regulating the power delivered by the receiver coil.

110. A system according to claim 109, wherein the characteristics of the power receiver comprise a Version Code and the transmitter is configured to operate in the first or second mode dependent on the Version Code.

111. A system according to claim 109, wherein the transmitter is arranged to transfer power to two or more receivers simultaneously in the second mode.

112. A system according to claim 107, wherein the characteristics of the power receiver include whether the power receiver comprises circuitry for controlling power flow to a load of the receiver.

113. A system as claimed in claim 107, wherein the controller extracts receiver device configuration information from modulated power signals passing between coupled transmitter and receiver coils and controls the mode of power transfer based on the configuration information, and the number of transmitter coils needed to power the receiver is controlled according to the configuration information.

114. A system as claimed in claim 107, wherein during a receiver location phase, prior to energy transfer, the controller selectively controls which one or ones of the transmitter coils are driven based on information received from the receiver as to a measure of signal strength received by the receiver from a driven transmitter coil.

115. A system as claimed in claim 114 wherein during a receiver location phase the control circuit sequentially connects a drive signal from the power conditioning circuit to each power transmitting coil to energise each coil for a predetermined time.

116. A system as claimed in claim 107, wherein the controller is arranged to detect the characteristics of the power receiver prior to transferring any power to the power receiver.

117. An inductive power transfer transmitter having one or more transmitter coils which can be selectively caused to transmit a power signal in a plurality of modes under control of a controller to a receiver coil of at least one power receiver, wherein the controller is configured to detect characteristics of the power receiver in order to control the mode of the power transfer,

wherein the power signal uses electromagnetic induction, and the characteristics of the power receiver are communicated from the receiver using modulation of the power signal.

118. A transmitter according to claim 117, wherein in a first mode the transmitter responds to power flow control communication from the receiver to control power flow by adjusting the amount of power being transmitted, and in a second mode the transmitter does not respond in this way.

119. An inductive power transfer transmitter as claimed in claim 118 wherein the characteristics of the power receiver include whether the power receiver includes circuitry for controlling power flow to a load of the receiver.

120. An inductive power transfer transmitter as claimed in claim 118 wherein the transmitter is arranged to transfer power to two or more receivers simultaneously in the second mode.

121. A transmitter as claimed in claim 117, wherein during a receiver location phase, prior to energy transfer, the controller selectively controls which one or ones of the transmitter coils are driven based on information received from the receiver as to a measure of signal strength received by the receiver from a driven transmitter coil.

122. An inductive power transfer receiver including:

i. one or more receiver coils; and

ii. a communication circuit which, upon receiving a power signal in the receiver coil from an inductive power transfer transmitter coil, transmits a signal to the inductive power transfer transmitter as to the characteristics of the receiver including whether the receiver includes a power flow controller for controlling power flow to a load of the receiver,

iii. wherein the power signal uses electromagnetic induction, and the characteristics signal of the power receiver are transmitted using modulation of the power signal.

123. An inductive power transfer receiver as claimed in claim 122 wherein the characteristics include version information, and wherein the version information indicates the mode of power transfer of the receiver.

124. An inductive power transfer receiver as claimed in claim 122 wherein the version information is sent in a packet subsequent to a signal strength packet.

125. An inductive power transfer receiver as claimed in claim 122 wherein in a first mode of operation the receiver communicates power flow control commands to the transmitter in order to adjust the amount of power being transmitted, and in a second mode the receiver controls the power flow to the load.