Hierarchical control for generator and battery in the more electric aircraft

This paper addresses the problem of intelligent power management for the more electric aircraft framework. The main objective is to regulate the power flow between a low voltage and a high voltage busses through control of a Buck-Boost converter unit. This approach allows the battery to help the generator when an overload scenario occurs, keeping at the same time the battery state of charge above a prescribed threshold. Moreover, in case a continued severe overload causes the battery state of charge to drop below a prescribed threshold, partial shedding of (noncritical) loads occurs. The control objectives are achieved through the design of a hierarchical control strategy based on high gain control for the low level and a finite state automaton for the high level control. Rigorous mathematical proofs of stability are provided for both low level and high level control and a detailed simulator with accurate model of the battery is presented in order to demonstrate the correctness and effectiveness of the proposed approach.