自谐振无线功率传输系统中线圈几何结构的性能比较

A self-resonant wireless power transfer (SRWPT) system offers exceptional reliability by eliminating the need for physical compensation capacitors. Planar coils with parasitic capacitance between adjacent layers are particularly ideal for such systems. The geometry of the coil significantly influences the performance of the WPT system. This paper thoroughly examines and compares four prominent coil geometries: circular, square, hexagonal, and octagonal. By optimizing the track-width ratio and track-gap ratio, the AC resistance of these PCB coils is markedly reduced, leading to highly efficient SRWPT systems. Comprehensive equivalent circuit models and theoretical frameworks for the inductance and capacitance of these PCB coils have been developed. The finite element method (FEM) is employed to optimize coil design and simulate performance. Four distinct SRWPT coils were constructed and subjected to rigorous experimental testing to evaluate their effectiveness. Results reveal that the hexagonal planar coil can transfer the highest power, at 82.3W, while the square coil achieves the highest efficiency of 93% and the highest quality factor of 54.