Optimizing air supply control of a PEM fuel cell system

The application of an LQG regulator on the air supply of a PEM fuel cell system showed significant improvements over the results obtained with PI controllers. The pressure trace was successfully decoupled from the mass flow trace and the response time of the supply was increased. This paper presents a dynamic model of the air supply. It accounts for the dynamics of the compressor and the manifold filling processes that are associated with the piping volume before and after the fuel cell. The model was verified on a testbench and showed good agreement between simulation and measurement. Furthermore, the limitations of a variable pressure strategy are discussed.