Analysis, design and implement of asymmetric coupled wireless power transfer systems for unmanned aerial vehicles

To solve the problem of short operating time of UAVs, this paper designs an asymmetric coupled wireless power transfer (WPT) system with optimized coupling structures and parameters, which effectively improves horizontal tolerance and performance for UAVs’ charging. Expressions of receiving power and transfer efficiency are derived to guide the design of parameters by modeling and analyzing the WPT systems. Structures and parameters of coupling coils are optimized to improve the quality factor and horizontal tolerance by simulations and comparison. System characteristics are further calculated and optimized with compensation topology. A prototype platform is implemented to verify the analysis and design, and experimental results show that it can achieve 64.87 W power transfer for UAVs with 57.94 % transfer efficiency, and the system is tolerant to horizontal misalignments of coupling coils. The analysis, design and implementation of asymmetric coupled WPT systems provides an important reference for the application of WPT technology in UAVs’ charging.