Real Time Fuzzy Energy Management of Fuel Cell and Ultracapacitor Powertrains

Energy management for systems presenting at least two energy sources is still a challenge. Moreover in Hybrid Electrical Vehicle the power must be managed in real time within system constraints. Energy management is based on efficiency models and data of both sources as function of the delivered power. With efficiency behavior knowledge, an optimization can be made. Logic rules are presented allowing the respect of power demand, power limits of the Fuel Cell System and State of Charge of the supercapacitors used as Storage Element System. The proposed two-step program, based on the fuzzy approach, manages the fuzzy membership functions by means of a simple genetic algorithm. Followed steps are described from the fundamental parameters’ identification stage to the optimization program structure able to manage in real time the energy flows in the HEV.