Control configuration selection for fuel cell stack systems

Dynamic characteristics and available on-line measurements in different types of fuel cell stack systems, e.g., proton exchange (polymer electrolyte) membrane (60-100C), molten carbonate (600-1000C), alkaline (90-100C), phosphoric acid (175-200C), oxide (600-1000C), and methanol (80-100C) fuel cells were evaluated. For each cell type, the adequacy of each measurement was determined in terms of its sampling period, time delay, level of uncertainty, and contribution to observability of the system. The partial pressure of hydrogen and membrane humidity was estimated using first-principle models. Apart from the partial pressure measurement inadequacy, the regulation of hydrogen in a PEM system was among the most challenging control problems. Insufficient supply of hydrogen caused "starvation" of the cell, leading to shorter life of the cell, while excessive hydrogen output from PEM reduced the cell efficiency. This is an abstract of a paper presented at the AIChE Annual Meeting and Fall Showcase (Cincinnati, OH 10/30/2005-11/4/2005).

Control configuration selection for fuel cell stack systems Conference Paper