Energy management strategy design based on frequency separation, fuzzy logic and Lyapunov control for multi-sources electric vehicles

This paper presents a new Energy Management Strategy (EMS) based on frequency separation and fuzzy logic control for a multi-sources system. The studied system is an electric vehicle with hybrid sources including a fuel cell (FC), a battery and an ultracapacitor. Each source is controlled using a DC/DC converter connected to the DC-bus. To maintain a constant DC-bus voltage, a Lyapunov based controller is developed. The overall energy flow of the system is managed using a filtering-based EMS which allows a flexible use of energy sources by self-adapting to the system state evolution. The proposed approach protects the fuel cell and the battery from strong power dynamics, and coordinates the distribution of the energy demand between the battery and the ultracapacitor according to their state of charge. Simulations on MATLAB/SIMULINK, using a real current profile in an urban driving situation, validate the performances of the proposed method.