Supervisory Energy Management of an Integrated Fuel Cell / Battery System for Vehicular Applications

Abstract

This work presents an energy management strategy (EMS) for an integrated fuel cell and battery system for vehicular applications. A challenging issue when integrating fuel cells to such applications is the handling of the dynamics that arise by their use. Additionally when a fuel cell is combined with a battery then various decisions should be made in order for the integrated system to operate in an optimum way, while fulfilling the frequently and rapidly changing load demand. In that context the resulting hybrid system should be complemented by a control system that will be able to handle the complex dynamics and the discrete decisions of the overall system. At the core of the considered control system an EMS is developed that dictates the appropriate decisions for each subsystem at various operating conditions. The goal of this work is to explore the behavior of the hybrid system under a realistic operation scenario which will be controlled by an EMS that relies on a Hybrid Timed Automaton (HTA). Besides the fulfillment of the load demand, the objectives of the EMS include the optimal use of the available hydrogen, the protection of the battery’s lifetime and the preservation of the fuel cell’s durability.