Method and system for performing foreign object detection in an inductive wireless power transfer system
First Claim
1. A method for performing foreign object detection in an inductive wireless power transfer system, the method comprising:
- obtaining measurements from a base station of a wireless power transfer system during charging;
determining transmitter energy loss in a power transmitter, Ptxloss, using the obtained measurements, wherein the transmitter energy loss, Ptxloss, is a function of at least Vcap and PTx,wherein Vcap is proportional to the voltage amplitude across the capacitor of an LC tank circuit in a power transmitter and PTx is a total power supplied to the power transmitter, and wherein Ptxloss is determined using a two variable model defined by an equation a*Vcap2+b*PTx+c, wherein Vcap and PTx are the measurements obtained from the base station of the wireless power transfer system; and
detecting the presence of a foreign object in response to the transmitter energy loss.
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Abstract
A method for performing foreign object detection in an inductive wireless power transfer system is disclosed. In the embodiment, the method involves obtaining measurements from a base station of a wireless power transfer system during charging and determining transmitter energy loss in a power transmitter, Ptxloss, using the obtained measurements, wherein the transmitter energy loss, Ptxloss, is a function of at least Vcap and PTx, wherein Vcap is proportional to the voltage amplitude across the capacitor of an LC tank circuit in a power transmitter and PTx is the total power supplied to the power transmitter. The method also involves detecting the presence of a foreign object in response to the estimated transmitter energy loss.
14 Citations
17 Claims
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1. A method for performing foreign object detection in an inductive wireless power transfer system, the method comprising:
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obtaining measurements from a base station of a wireless power transfer system during charging; determining transmitter energy loss in a power transmitter, Ptxloss, using the obtained measurements, wherein the transmitter energy loss, Ptxloss, is a function of at least Vcap and PTx, wherein Vcap is proportional to the voltage amplitude across the capacitor of an LC tank circuit in a power transmitter and PTx is a total power supplied to the power transmitter, and wherein Ptxloss is determined using a two variable model defined by an equation a*Vcap2+b*PTx+c, wherein Vcap and PTx are the measurements obtained from the base station of the wireless power transfer system; and detecting the presence of a foreign object in response to the transmitter energy loss. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An inductive wireless power transfer system, the inductive wireless power transfer system comprising:
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a base station comprising; a system unit; at least one power transmitter coupled to the system unit, the at least one power transmitter having a power conversion unit and a communications and a control unit; wherein the inductive wireless power transfer system is configured to perform foreign object detection, foreign object detection comprising; obtaining measurements from a base station of a wireless power transfer system during charging; determining transmitter energy loss in a power transmitter, Ptxloss, using the obtained measurements, wherein the transmitter energy loss, Ptxloss, is a function of at least Vcap and PTx, wherein Vcap is proportional to the voltage amplitude across the capacitor of an LC tank circuit in a power transmitter and PTx is a total power supplied to the power transmitter, and wherein Ptxloss is determined using a two variable model defined by an equation a*Vcap2+b*PTx+c wherein Vcap and PTx are the measurements obtained from the base station of the wireless power transfer system; and detecting the presence of a foreign object in response to the transmitter energy loss. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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17. A non-transitory computer-readable storage medium storing instructions to be executed by a computerized system for:
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obtaining measurements from a base station of a wireless power transfer system during charging; determining transmitter energy loss in a power transmitter, Ptxloss, using the obtained measurements, wherein the transmitter energy loss, Ptxloss, is a function of at least Vcap and PTx, wherein Vcap is proportional to the voltage amplitude across the capacitor of an LC tank circuit in a power transmitter and PTx is a total power supplied to the power transmitter, and wherein Ptxloss is determined using a two variable model defined by an equation a*Vcap2+b*PTx+c wherein Vcap and PTx are the measurements obtained from the base station of the wireless power transfer system; and detecting the presence of a foreign object in response to the transmitter energy loss.
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Specification