Energy management of a fuel cell serial-parallel hybrid system

A serial-parallel hybrid (SPH) fuel cell system which include control and protection loops are presented in this article. The hybrid system is formed by a Fuel Cell (FC), an Auxiliary Storage Device (ASD), and the current-controlled dc-dc converters responsible for the management of the energy between FC and ASD in a serial-parallel topology. The main advantages of the selected converter are its voltage step up and step down properties, high efficiency, and low input and output current ripples. This allows it to be positioned in the different FC hybrid system localizations with a suitable design of its control. Moreover, having the same module for all the system converters simplifies the design and construction tasks. The theoretical analyses have been simulated on a 48 V, 1200 W dc bus.