Design of control methods for a portable PEMFC power system

Based on intelligent control theory each part of a portable PEMFC (proton exchange membrane fuel cell) power system was designed and the key factors that affect performance of the system were analyzed, then some measures were taken to control these factors to make the system run well. The oxidant (air) is provided by two DC fans whose speed are self-adjusted, and they are also used to keep the system in the appropriate temperature range. The water atomized by ultrasonic is transported together with air to humidify the PEM (proton exchange membrane), and the amount is adjusted as the output power of the system changes. Exhaust is let intermittently, and the interval and once-persisting time is self-adjusted. Also the control circuit with a single chip microcomputer as heart and the software were designed. Finally a prototype of 200-watt PEMFC power system with above control methods was tested, and the result was satisfying.