Fuzzy Logic control strategy for Fuel Cell/Battery aerospace propulsion system

This paper presents power control strategies for the propulsion of unmanned arial vehicle (UAV) which is driven by fuel cell/battery hybrid system. UAV propulsion system has different power requirements in order to complete its mission successfully. The different power stages in propulsion system introduce in flight taxing, take off, cruising and landing. The specific feature of the UAV is that power needed for the pay load which consists with sensors and communication devices is high compared with small manned aircraft. As the power sources, fuel cell has high energy density and battery has high power density which limited to short period. Fuel cells introduce challenges with dynamic load variations due to uncertain load requirements. These variations could cause the fuel cell to operate outside its optimum efficiency margin. In this paper, UAV Fuel Cell propulsion system is integrated with the battery source and controlled via a suitable Fuzzy Logic methodology also combined with an intelligent based approach for establishing the power converters duty-cycle modes of operation. Two power controllers are designed to adapt to the load variations and optimizes the fuel cell operation by utilizing the battery (Li-Ion) source in an effective manner. The intelligent based duty-cycle modes allows the power converters of fuel cell and battery to operate at the appropriate mode hence taking into account the systempsilas energy sources states of charge (SOC). Finally endurance of the Fuel cell powered hybrid UAV can improve significantly.