Control of fuel cell/battery/supercapacitor hybrid source for vehicle applications

This paper presents a control algorithm for utilizing a polymer electrolyte membrane fuel cell (PEMFC) as a main power source and storage devices (batteries and supercapacitors) for DC distributed system, particularly for future FC vehicle applications. This strategy is based on a standard DC bus voltage regulation, which takes into account the slowest dynamics of a fuel cell (FC) and the fastest dynamics of a supercapacitor bank. The principle is based on frequency approach that the FC dynamics are limited to avoid fuel starvation problems and the battery dynamics are also limited to reduce its stress. Its originality lies in using only the supercapacitor for supplying the energy required to achieve the DC bus voltage regulation, the battery for supplying the energy to keep the supercapacitor charged, and the FC for supplying the energy to keep the battery charged. To validate the proposed principle, a hardware system is realized by analog circuits and numerical calculations by dSPACE. Experimental results with small-scale devices (a PEMFC: 500-W, 50-A; a battery bank: 68-Ah, 24-V; and a supercapacitor bank: 292-F, 30-V) authenticate the excellent control algorithm during motor drive cycle.