Air supply system of a PEMFC stack dynamic model

A typical air supply system for a Proton Exchange Membrane Fuel Cell (PEMFC) stack consists of a compressor, a humidification device, the fuel cell stack, and a pressure control valve. In this paper, a dynamic model for such an air supply system is developed. The model considers the filling/emptying dynamics of the manifolds (which re present the volumes between compressor, fuel cell stack, and valve), the dynamics of the compressor/E-motor unit, and the inertial effects in the inlet manifold. Validation of the model is performed with measurements obtained from a 6 kW(e) 100-cell stack test bench, which was designed and constructed with the objective of reproducing typical operating conditions for automotive applications. On the basis of this model, a model-based controller can be designed to reduce the system response time to load changes. Furthermore, in this paper an empirical model is proposed, which describes the cell voltage variation across the stack for different operating conditions.