This work presents the modeling, control design, and simulation of a Cirrus SR20 with a hybrid electric propulsion (HEP) system composed of a combustion engine and battery-supplied electric drive that operates in one of two modes: 1) battery discharging and electric drive propelling, and 2) battery charging and electric drive generating. Given a supervisory-level system model, two optimization control problems are developed. The first finds the elevator deflection and propeller shaft power and speed that minimizes the desired flight profile tracking error. The second manages HEP power flows to provide the desired propeller shaft power while trading off fuel use and battery charge level deviation. The second optimal control problem is a switched problem that requires optimization over discrete and continuous control inputs. The problem is solved using an embedding method that relaxes the discrete valued inputs to continuous values to avoid computational complexity associated with alternate approaches. The resulting model predictive control is demonstrated with simulation of two flight profiles: sawtooth-shaped altitude profile while maintaining constant velocity and an experimental one taken from a production aircraft. Simulations show good profile tracking and appropriate power management. The HEP-equipped aircraft demonstrates a 15.6% fuel savings over the experimental profile; further, the proposed control achieves a 4.3% savings over a rule-based approach under certain conditions.
Hybrid Electric Aircraft Switched Model Optimal Control
Journal of Propulsion and Power ; 36 , 4 ; 488-497
2020-06-17
10 pages
Article (Journal)
Electronic Resource
English
Optimal energy management for hybrid-electric aircraft
Emerald Group Publishing | 2020
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