Design and Implementation of a PEMFC/Battery Hybrid Generation System with Bi-Directional Power Flow

This study presents a digital controller based fuel cell generation system with secondary batteries for balancing power flow. The system consists of a ZVS-FB dc/dc converter, which connects with the fuel cell output-end, to hold the DC bus constantly and to translate power to a single phase inverter effectively. A bi-directional dc/dc converter that connects between fuel cells and batteries is able to regulate the output current of the fuel cell and the charging current/voltage of the battery while limiting the discharging current of the battery. Besides the construction of the system, the flexible control strategy that induces in several different objectives is necessary for active power sharing and energy storage. A 500 W system is tested to verify that the power converters can be regulated appropriately to meet the adaptive voltage/current of the battery and the fuel cell and the fixed DC bus voltage