Metal object detection with high sensitivity and blind-zone free for DD coil-based wireless electric vehicle chargers

In this paper, a metal object detection (MOD) for wireless electric vehicle charger (WEVC) employing DD coils is proposed. Conventional single-layer symmetric coils exhibit reduced sensitivity near the coils and blind-zone along their symmetry axis. To address these limitations, we propose a dual-layer MOD coil configuration. And in this configuration, the second coil layer features rectangular coils in the less sensitive regions, and an optimal concave-convex coil design is given. By using the configuration, the proposed design can enhance the sensitivity and overcome the blind-zone challenges. Finally, simulation and experimental results also show the effectiveness and robustness of the proposed design, which can also be used to improve the detection capability in wireless power transmission applications.