Nonminimum-phase phenomenon of PEM fuel cell membrane humidifiers / Chen, Dongmei in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 130 n°4 (Juillet 2008)  

Nonminimum-phase phenomenon of PEM fuel cell membrane humidifiers [texte imprimé] / Chen, Dongmei, Auteur ; Huei Peng, Auteur . - 2008 . - 9 p.
dynamic systems
Langues : Anglais (eng)
in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 n°4 (Juillet 2008) . - 9 p.

Mots-clés :	air flow  humidifiers  membranes  vapors  temperature  water  fuel cells
Résumé :	A membrane-based humidifier that uses cooling water of a fuel cell system to humidify the inlet air is modeled and analyzed in this paper. This four-state lumped model is simple and yet captures the humidification behavior accurately. A peculiar characteristic of this system is the fact that it exhibits nonminimum-phase (NMP) behavior. The reason the NMP behavior exists and the effect of system parameters on the location of the NMP zero are analyzed. A proportional control algorithm is proposed to reject the effect of system disturbances, and a feed-forward algorithm is developed to ensure proper humidifier operation under air flow rate changes. Because the NMP zero exists in the disturbance-to-output loop, the proposed algorithm was found to successfully eliminate the undershoot phenomena associated with the NMP zero. However, the disturbance-to-output loop is coupled with input-to-output loop, and the NMP zero could affect the feedback control design.
En ligne :	http://dynamicsystems.asmedigitalcollection.asme.org/issue.aspx?journalid=117&is [...]