A new control strategy for stand-alone fuel cell-battery hybrid power supply system

In this paper, a new control strategy is proposed for a stand-alone fuel cell-battery hybrid power supply system. This new control strategy can both meet the high peak power load demand and preserve a high energy density and thus ensures a high quality power supply. The fuel cell output current is adjusted according to state of charge and voltage of the battery. The battery is charged in a proper way when state of charge is below a chosen limit. Furthermore the new strategy can mitigate the load transient to ensure a long life time for fuel cell. The control strategy is implemented in Visual Simulation (Vissimtrade), together with a dynamic proton exchange membrane fuel cell (PEMFC) model and a lead acid battery model, and tested under different conditions. The simulation results demonstrate that the control strategy is valid and can meet the load demands.