Feedback linearization based air pressure and mass flow rate regulation for PEMFCs

In Polymer Electrolyte Membrane Fuel Cells (PEMFCs), precise regulation of air pressure and flow rate is critical to the performance and durability of fuel cell systems. This study is based on a 20-kW fuel cell engine. Based on physical interpretation and data, a nonlinear model of the cathode of the fuel cell system is presented in this paper. By utilizing the basic idea of differential geometry, the nonlinear model is further exactly linearized via coordinate transformation. Optimal controller design methodology is then adopted to construct a Linear Quadratic Regulator (LQR) for air pressure and flow rate regulation. Finally, the effectiveness of the controller is validated by the experimental results.