Date of Award

12-2017

Degree Name

Master of Science in Engineering

Department

Mechanical and Aerospace Engineering

First Advisor

Dr. Richard T. Meyer

Second Advisor

Dr. Peter A. Gustafson

Third Advisor

Dr. Tianshu Liu

Access Setting

Masters Thesis-Open Access

Abstract

This work presents the switched optimal power flow control for an aircraft with a hybrid electric propulsion system. The propulsion system is a switched system that operates in either of two modes: (i) battery discharging and electric motor propelling and (ii) battery charging and electric motor generating. The aircraft model and components that form the hybrid propulsion system are modeled as either an algebraic power source/sink or as a dynamic model with appropriate power and state interconnections. With the system model defined, a model predictive control power management strategy is set fourth which minimizes a performance index that includes altitude and velocity tracking errors, fuel use, and battery charge level. The switched system model predictive control problem is solved using an embedding approach that relaxes the discrete-valued mode control variables to continuous-valued ones. The solution of the continuous-valued problem results in the optimal power flow which reasonably tracks desired flight profiles while considering the efficient use of the hybrid powerplant. The proposed power management is demonstrated with an aircraft based on the Cirrus SR-20.

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