In this study, a control strategy for direct methanol fuel cell (DMFC) systems is presented. By utilizing the specific impedance measurement, high frequency resistance (HFR) and charge transfer resistance (CTR), as the linguistic variable, this control strategy, based on the fuzzy logic, can distinguish the humidification conditions in a stack. Thus, with the efficient computation of the fuzzy controller, the stoichiometric flow for the air supply of the DMFC is varied to prevent the performance drops caused by flooding and drying. It is sufficient to assist the stack in reacting at an optimal operating state. Furthermore, this methodology reduces the measuring time of impedance and can real-time control the behaviors of a practical DMFC system. Although the influences of operating temperature on the state of system are not accounted, this fuzzy controller has the adaptability to run even if the stack is operated at various temperatures.
INTERNATIONAL JOURNAL OF INNOVATIVE COMPUTING INFORMATION AND CONTROL