Objective At present, the application of wireless power transmission technology on Unmanned Aerial Vehicle (UAV) is becoming a research hotspot, but the endurance of UAV remains one of the main bottlenecks in development.

Method  This paper proposed a wireless power transmission system with strong coupling capability and capable of realizing constant voltage output for small and medium-sized UAV. Compared with the current mainstream multi-rotor UAV wireless charging system, this design scheme utilized the underdamped resonance principle to realize high-frequency inversion through a single transistor, which replaced the full-bridge and half-bridge inverter with a more miniaturized and lightweight one. And it avoided the bridge arm direct conduction problem and improved the stability of the circuit. Meanwhile, the LCC-S/CLC compensation topology realized the constant current/constant voltage output based on the magnetic coupling resonant wireless power transmission system. The design of the magnetic coupler not only enhanced the coupling capability between the receiving side and the transmitting side of the coupling coil, but also reduced the number of turns of the coil on the receiving side, meeting the lightweight requirements of UAVs.

Result Finally, a simulated UAV charging experimental platform with a rated power of 100 W is built with 25 V input, and the peak efficiency can reach 92%.

Conclusion The simulation and experimental results verify the theoretical analysis and calculation and prove the feasibility of the wireless power transmission system based on a single-transistor inverter.