Method of Non-blind-zone Foreign Object Detection in Wireless Power Transfer System

A non-blind-zone Foreign Object Detection (FOD) scheme in Wireless Power Transfer (WPT) system is proposed, based on the impedance characteristics of the detection coil with double-layer structure. In this scheme, a double-layer coil is designed through the partition of the detection coil to achieve the uniformity of the distribution of the magnetic field, so as to improve the detection accuracy and eliminate the blind zone on the certain size of metal foreign object. Then, through the analysis of experiments, the sensitivity and the stability of metal FOD system are verified. It is shown that the designed system can detect the metal foreign object as small as a paper clip without blind zone whether the strong power magnetic field exists or not.

Automated summary

This paper proposes a non-blind-zone Foreign Object Detection (FOD) scheme in Wireless Power Transfer (WPT) system, based on the impedance characteristics of the detection coil with double-layer structure. Through the design of a double-layer coil, the distribution of the magnetic field is made uniform, improving detection accuracy and eliminating blind zones for certain sizes of metal foreign objects. Experimental analysis verifies the sensitivity and stability of the metal FOD system, showing that it can detect metal foreign objects as small as a paper clip without blind zones, regardless of the presence of a strong magnetic field.