Ultra High Speed Generator System with Microturbine Engine for Hybrid-powered UAV Application

Extended endurance and high payload capacity are the important objectives for unmanned aerial vehicle (UAV). However, due to limitations in energy density of batteries, the prospects for improving the endurance and payload capacity of electric UAVs are extremely restricted. This paper proposes a ultra-high-speed power generation system for hybrid-powered UAVs. The power generation system uses a turbine engine as the power source to drive a high-speed generator for generating high-frequency alternating current, which is then rectified and connected to the DC power grid inside the UAV. To increase rectification efficiency while ensuring grid connection with the power lithium battery, an active rectification control method based on field-oriented control is employed, and closed-loop control is implemented to achieve output voltage tracking of the lithium battery voltage. Furthermore, this paper also introduces a method for emergency energy dissipation of the generator to prevent over-speeding of the engine and generator when the load is suddenly removed. Experimental simulations have demonstrated that the proposed system is capable of effectively achieving rectification, power control, and other functions. Additionally, it promptly responds to sudden load removal, thereby preventing over-speeding accidents. The power generation system is expected to significantly enhance the endurance and payload capacity of UAVs. Furthermore, the proposed system architecture can serve as the core for the next generation of large hybrid-powered aircraft.