Foreign Object Detection for Wireless Power Transfer

This paper presents foreign object detection (FOD) methods for MHz wireless power transfer (WPT) systems. Unlike current FOD implementations, the presented methods can operate without requiring a feedback loop from the wireless power receiver to the transmitter. This allows complete decoupling of the transmitter and receiver and therefore reduces the design complexity and cost of the system. The developed FOD methods were implemented on a 13.56 MHz WPT and experimental results are presented showing successful detection of a wide range of objects regardless of the loading condition of the system.