Design and Optimization of a Misalignment‐Tolerant WPT System Based on Non‐Identical Transmitter and Receiver Coils

ABSTRACT This paper addresses the issues of poor misalignment tolerance and unstable inductance in the coils of wireless power transfer (WPT) systems for electric vehicle (EV), proposing a novel coil design scheme based on non‐identical of the transmitter and receiver coils. On the receiver side, a naturally decouplable coil structure achieves natural decoupling, suppressing unwanted cross‐coupling without extra components. On the transmitter side, the coil's physical size is increased to enlarge the power transfer area, while its number of turns is reduced to keep its self‐inductance consistent with the receiver coils. Applying this design to a 2 × 2 coil array significantly improved the system's tolerance to both lateral and rotational misalignment. During misalignment, the coils' self‐inductance showed minimal variation. This stability in resonant circuit parameters effectively prevented the typical drop in power transfer efficiency caused by inductance changes. Tests on a scaled prototype confirmed the improvement. Within the lateral misalignment range of 0–200 mm and under rotational misalignment angles of 0°–360°, the coil structure proposed in this work maintains a power transfer efficiency of over 90%, while also exhibiting significantly reduced self‐inductance fluctuations compared to conventional identical coil structure. The fluctuation in self‐inductance was also markedly reduced. These results demonstrate the feasibility and robustness of the proposed coil design for practical EV wireless charging.