Fuel cell and power control for a hybrid vehicle. Experimental results

This work presents the design, implementation and experimental evaluation of the control system for a Fuel Cell Hybrid Vehicle (FCHV). The main objective of this paper is to develop control strategies for a real vehicle which has been designed in order to demonstrate the feasibility of the use of hydrogen as an energy source for automotive applications. The hybrid vehicle is driven by an array of batteries and a bank of two fuel cells. The control system is designed and tested in order to perform all the operations related to the coordinated operation of the fuel cells, the intermediate electrical storage and the power train. Real-time power management is done in order to satisfy the power demand of the electric motor taking into account the state of charge of the batteries and the operating regime of the fuel cells. An embedded controller has been installed to manage the power distribution between the fuel-cell bank and the batteries and a supervisor has also been designed and tested. An important contribution to be noticed is the development of a power management strategy devised to split the power between both fuel cells. Besides, a low-level controller has been implemented to regulate temperature and air excess ratio in the cells. Some experimental results are presented in order to show the vehicle performance. The proposed hybrid vehicle, tested under real driving conditions, has demonstrated a high robustness and reliability.