Supervised Energy Management in Advanced Aircraft Applications

A control strategy is proposed for energy management onboard the innovative More Electric Aircraft (MEA) concept. The objective is to reduce generator sizing (and weight onboard) by using battery packs as extra-energy sources. The flow of energy is regulated by a Buck-Boost Converter Unit (BBCU), suitably driven. The controller is composed of a two-layers architecture, where the bottom layer is devoted to current-tracking purposes, while the upper level takes care of the safe switching between the different control objectives. Rigorous stability tools are presented for both controllers, based on the Theory of Sliding Mode Control and of Common Lyapunov Functions. Detailed simulation with switching power electronic components show the effectiveness of the proposed approach.

I. Introduction

The interest of the aeronautic factories towards the More Electric Aircraft (MEA) is continuously growing in the last two decades. MEA concept essentially has the objective to replace as far as possible hydraulic and pneumatic devices with their electric counterpart. There are many reasons for this increasing interest [1]. First, the flexibility in use and the good reliability electric devices have when compared to hydraulic and/or pneumatic counterparts. For example, replacing hydraulic actuators for the aircraft control surfaces with electromechanical (EMA) or electrohydrostatic (EHA) actuators [2], results in weight reduction, as the whole central hydraulic system can be removed, increased reliability, since a local fault has just a local effect and does not propagates along the actuators’ supply pipe, and increased efficiency, typical of electric motors wrt their hydraulic counterpart. Moreover, energy-saving techniques specific of electric motors, e.g., regenerative breaking, can be considered in order to reduce energy consumption [3], [4].