Apparatus, system, and method for detecting a foreign object in an inductive wireless power transfer system

摘要

An inductive wireless power transfer system comprises a transmitter configured to generate wireless power signal to a coupling region in response to an input signal. The inductive wireless power transfer system's control logic is configured to determine an input power of the input signal. The control logic is configured to determine a presence of a foreign object within the coupling region in response to a comparison of the input power and an output power of an output signal of a receiver within the coupling region. Related inductive wireless power transfer systems and methods for detecting a foreign object in an inductive wireless power transfer coupling region of an inductive wireless power transfer system are disclosed.

主权项

1. An inductive wireless power transfer device, comprising:
a transmitter configured to transfer power to a receiver in a coupling region by generating a wireless power signal in the coupling region in response to an input signal; a current sensor configured to measure a direct current (DC) current of the input signal; a voltage sensor configured to measure a DC voltage of the input signal; and control logic coupled to the current and voltage sensors and configured to:
determine, based on the measured DC current and DC voltage of the input signal, an input power of the input signal while power is being transferred to the receiver via the wireless power signal;determine a transmitter power loss of the transmitter;determine a receiver power loss of the receiver;determine an output power of an output signal at the receiver based on information received from the receiver;determine a coupling coefficient power loss in the coupling region between the transmitter and the receiver;determine a foreign object power loss based on the input power, the transmitter power loss, the receiver power loss, the output power, and the coupling coefficient power loss;determine a presence of a foreign object within the coupling region based on the foreign object power loss;reduce a strength of the wireless power signal when the foreign object power loss is above a first predetermined threshold and below a second predetermined threshold; andstop generating the wireless power signal when the foreign object power loss is above the second predetermined threshold.