Design of 8-Plate Mixed-Coupling Wireless Power Transfer Coupler with Complementary Modes for AGV Charging Under Rotational Misalignment

This paper proposes a coupling-path reconfigurable mixed-coupling wireless power transfer (CPRMPT) coupler for improving coupler-level transmission stability under rotational misalignment. The proposed coupler forms two coupling modes, namely the adjacent coupling path (ACP) and diagonal coupling path (DCP), by changing the feeding polarity arrangement within the same physical structure. An equivalent-circuit model is used to describe the mode-dependent synthesis of self and mutual LC components, and 3D full-wave analysis is performed under a 100 mm transfer distance and 0–180° rotational conditions. The ACP mode maintains a near-unity maximum transmission coefficient over most rotation angles but shows a transmission null at 90°. In contrast, the DCP mode maintains near-unity transmission at 0°, 90°, and 180°, while null points occur at 45° and 135°. The extracted mutual parameters show that the ACP Lm and Cm decrease from 5.35 μH and 0.052 pF at 0° to nearly zero at 90°, whereas the DCP mutual parameters decrease to nearly zero at 45° and 135°. These results demonstrate that coupling-path reconfiguration can provide complementary transmission paths for rotation-tolerant MPT coupler design.