Dynamic modeling and validation studies of a tubular solid oxide fuel cell

Solid oxide fuel cell (SOFC) is a key component in the new vision of distributed power generation. However, for connecting SOFC reliably to a load-varying grid, its transient behavior needs to be studied in detail with a thoroughly validated dynamic model. Dynamic models are also important for synthesizing efficient controllers. In this paper, a detailed dynamic model of a tubular SOFC is validated using experimental data from an industrial cell operating over a broad operating range. Steps in voltages and flows are used to study the system response. In the process of validation, phenomena that affect the transient response of the cell significantly are identified. The effects of Knudsen diffusion along with that of the increased active area for the electrochemical reactions are considered in this model observing the deviations of the simulation results from the experimental data. A dynamic model that includes these effects provides a very good match with the experimental data. Characteristics of the transient responses and various nonlinearities in the fuel cell dynamics are also studied in detail.