Metal Object Detection With Detection Coils Perpendicular to Power Coils for Wireless Power Transfer Systems

In this letter, a metal object detection (MOD) method with detection coils perpendicular to power coils is proposed. Without a metal object, the induced voltage in the detection coils is ideally zero. When a metal object falls on the top of the Tx pad, an eddy current is induced, and this eddy current in the metal object will induce a voltage in the detection coils. The proposed method can perform well with misalignments between the Tx and Rx pads. No adjustments are required for different winding positions. The concept is well verified with experimental results.

Automated summary

In this letter, a method for metal object detection (MOD) is proposed, using detection coils perpendicular to power coils. The theoretical voltage in the detection coils is zero when no metal object is present. However, when a metal object is placed on the Tx pad, it induces an eddy current, resulting in a voltage in the detection coils. This method is able to function well even with misalignments between the Tx and Rx pads, and does not require adjustments for different winding positions. The concept has been successfully validated through experimental results.