Integration of PEM Fuel Cells and Lithium Ion Secondary Battery into a Single Hybrid Electric Energy Source – Part I: Control System

Both fuel cells and lithium-ion cells are chemical sources of electric energy. In either of these sources, energy is obtained from chemical reactions performed at the electrodes. However, different constructions of those cells causes that they are characterized by different, and in many cases opposite, properties. Their combination into a single hybrid power source can therefore lead to utilization of advantages of both of them and, at the same time, mutual elimination of their disadvantages. The article presents control assumptions, structure of control system and control algorithm of a hybrid portable electric energy source in an early stage of development – a technology demonstrator. Discussed technology demonstrator integrates PEM fuel cells with Li-ion secondary cells.