Hybrid Electric Aircraft with Unlike Engine Degradation Using Model Predictive Control

The aviation industry is currently undertaking a revolution where either all-electric or hybrid-electric propulsion systems are becoming feasible and being considered for commercial transportation applications. The addition of electrical power systems to the propulsion system allows for the coupling of previously independently operated gas turbine engines. Commercial aircraft propulsion systems typically consist of multiple engines that may not degrade at the same rate. Asymmetric degradation on a multi-engine aircraft causes asymmetric thrust output from each engine. A hybrid-electric aircraft power and propulsion system architecture with electrified turbomachinery enables the power transfer between engines to balance asymmetric thrust. The concept, titled Hybrid-Electric Aircraft with Unlike Engine Degradation, utilizes a decentralized proportional-integral-based control approach to balance thrust production between the engines by transferring electrical power from a healthier to a more degraded engine. Building on this approach, this study presents a centralized model predictive controller (MPC) in lieu of the previous architecture to address constraint adherence and remove the need for multiple controllers. Simulation results are presented at varying engine degradation levels on a nonlinear hybrid-electric powertrain. Results show that the MPC successfully consolidates the previously decentralized control architecture into a single, centralized control scheme with the ability to balance thrust while subject to system constraints.