Key words: PEM fuel cell, dynamic response, time constant.
The designated application of PEM fuel cell is for mobile systems, in which the power supply is given by the fuel cell output. In such mobile systems, one of the most important performance parameters could be the dynamic response time constant, which essentially accounts for the time needed for the automobile to response to the order from the driver. This so-called time-elapse shall fall within 1 second for internal combustion engine automobile, especially for those high performance sports vehicles shall even less than 0.1 second. For the fuel cell vehicles, the time-elapse shall not be longer than that of internal combustion engine vehicle, and which is a complicate integration of all the possible time constants of each component of the fuel cell. The present project is proposed to examine such a time constant, while the time constants of each component will be examine separately and then an integration of all the constants will an analyzed. We will examine this from two aspects: One is from analytical analyses in which the mathematical models will be established and to be solved either analytically or numerically, depending its own needs. The other is from experimental measurements in which different fuel cell designs will be employed and conducted under different operational conditions. These two parts of research will be examined altogether to determine the time constant for the system as far as the constants of each component have been identified.
Key words: PEM fuel cell