ABSTRACT
This chapter describes the various models of polymer electrolyte membrane fuel cells (PEMFC). It also describes the results obtained from a sensitivity analysis performed on an input–output transfer function that is derived from the linear small-signal model of PEMFC dynamics proposed by Chiu et al. The chapter explores the equivalent circuit modeling of direct methanol fuel cell dynamics from measured temporal responses during step changes in load current at various temperature and fuel flow-rate operating conditions as proposed by Singh et al. Since the PEMFC’s dynamic behavior is inherently nonlinear, any linear model of those dynamics is only an approximation of the original nonlinear equations. MATLAB was used to perform simulations of PEMFC dynamic response based on the small-signal linear state-space models. A partially linearized model of PEMFC dynamics is applied, where the partial pressures of hydrogen, oxygen, and water in the fuel cell were each modeled as having first-order dynamics.
