System Identification of Small-power Proton Exchange Membrane Fuel Cell System

• Main Authors: Ming-Hao Liu, 劉明皓
• Other Authors: 陽毅平
• Format: Others
• Language: en_US
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/88812639463842574074

碩士 === 國立臺灣大學 === 機械工程學研究所 === 94 === Based on electro-chemical reactions, the small-power fuel cell system is simplified as a coupled multi-input and multi-output system. Utilizing the pseudo random binary sequence as the input and ARMAX as the model, system identification is performed at different operating points. Both fixed-valued parameters and time-varying parameters are used in ARMAX in order to find a suitable model. According to the identification result, ARMAX models with fixed-valued parameters can not describe the system dynamics suitably, while models with time-varying parameters can. System dynamics are also proven to be insensitive to temperature changes between 35 and 45°C. It is also shown that when the hydrogen stoichiometry is over 1.2, fast changes of the hydrogen flow rate does no influence on the fuel cell system performance.