Key technologies of fuel cell unmanned aerial vehicles and hybrid energy architecture

In the field of long-endurance hydrogen-powered unmanned aerial vehicles, hydrogen fuel cell power systems demonstrate more significant applicability compared to turbine engine power systems. This paper delves into the current development status of long-endurance fuel cell unmanned aerial vehicles, analyzes and summarizes the characteristics and applicable scenarios of typical large-scale hydrogen fuel cell unmanned aerial vehicles, and studies the key technologies that restrict the development of long-endurance hydrogen fuel cell unmanned aerial vehicles. It comprehensively reviews the domestic and international development status. A design scheme for a large-scale hydrogen energy unmanned aerial vehicles with the maximum flight time as the optimization objective is proposed, and the overall layout design is carried out. Different power architecture forms are compared, and a hydrogen fuel cell-lithium battery hybrid power system structure is selected. The design of power system scheme, electric motor, liquid hydrogen fuel storage, and energy management strategy are carried out. Based on the finite state machine idea, an energy management control strategy is constructed. Simulation results show that under typical constant-speed cruise conditions and two variable-power conditions, this strategy can ensure that the fuel cell always operates at the optimal power output while meeting the overall power demand. The lithium battery discharges when the load demand power is large and charges when the load demand power is small, effectively ensuring the reliability of the power system. This provides a reference for the design of large-scale unmanned aerial vehicles with fuel cell-lithium battery hybrid energy power system.