Hybrid power sources composed of fuel cells and secondary batteries can combine the high energy density of fuel cells with the high power density of batteries. A dc/dc power converter can be placed between the fuel cell and the battery to balance the power flow and greatly augment the peak output power. This paper presents a novel, flexible strategy for multiobjective control of the power converter in the hybrid power source. The control strategy is able to regulate the output current of the fuel cell and the charging current or voltage of the battery while limiting the discharging current of the battery. It can be used in two different configurations without any change. The control strategy is implemented in MATLAB/Simulink and tested by simulation and experiments. Simulation and experimental results show that the multiobjective control strategy is able to select the regulation mode correctly and the fuel cell current, battery current and battery voltage are regulated appropriately. Experiment results demonstrate the great flexibility and generality of the control strategy and validate that the peak power capacity of the active hybrid power source is increased significantly. Simulation and experiment results also show that power converter can be appropriately regulated to meet the multiple objectives required by hybrid power sources.
Published in IEEE Transactions on Power Electronics, Volume 20, 2005, pages 244-253.
© 2005 by IEEE