Design and Optimization of Wide-Coupling Nested Magnetic Coupling Mechanism for UAV Wireless Power Transfer

Within the UAV sector, wireless power transfer applications face challenges due to inaccuracies in landing positioning and docking control, leading to misaligned docking and variable offset ranges. The existing magnetic coupling mechanisms offer limited power supply areas, insufficient to meet the demands of random loads across a wide range of positions. This paper focuses on the magnetic coupling mechanism of UAV wireless power transfer systems and proposes a nested UAV wireless power transfer system for a broad coupling region to expand the power supply area and ensure stable power distribution. Employing finite element numerical analysis, the spatial magnetic field generated by the nested emission module is examined, revealing the distribution characteristics of magnetic induction intensity above the module. A "cross-shaped" compensation coil is designed to address coupling blind spots within the power supply area. A coupling performance evaluation method based on optimal magnetic coupling regions is introduced to determine the optimal parameters for the nested magnetic coupling mechanism, along with a general expansion process for multi-stage embedded coils. Further, by analyzing the cross-coupling state between receiving coils, the spatial arrangement of the receiving end coils is delineated, and their structural parameters are established. An experimental platform for the nested UAV wireless power transfer system is constructed, demonstrating that within the proposed optimal coupling region, power fluctuations are less than 25%, and the magnetic coupling mechanism provides a wide, stable, and reliable power reception area for random loads