On a NMPC-based supervisory control logic for Energy Management purposes in Aeronautical Hybrid Propulsion Systems

Eco-sustainability is one of the main aspects focused on motor industries, including those related to air transport, which work to realize alternative propulsion systems, such as Hybrid Electric Propulsion Systems, for reducing CO2 emissions. Despite the minor CO2 emission produced by Hybrid Electric Propulsion Systems, these categories of propulsors require a proper control architecture for managing combustion and electric energies based on driver decisions and the flight mission set. A supervisory control logic, based on a Nonlinear Model Predictive Control (NMPC), is presented in this work to guarantee a specific State of Charge level of batteries coupled with the minimization of fuel consumption of an aeronautical Hybrid Propulsion System. These two goals are achieved by the designed NMPC, which provides the best amount of torque between the propulsors belonging to the analyzed aeronautical powertrain, consisting of an Internal Combustion Engine and an Electric Machine. The proposed NMPC performances are tested by a map-based model of the previously mentioned propulsors, included in a lumped parameters modelling related to the longitudinal dynamics of a Single Engine aircraft. The comparison between the same aircraft equipped with a Hybrid Propulsion System and a conventional Internal Combustion Engine demonstrates the suitability of the proposed NMPC to be adopted for improving eco-sustainability by reducing CO2 emissions.