In this paper a feedforward-feedback control design for solid oxide fuel cell (SOFC) power systems is proposed. The feedforward part of the controller reacts to the electrical current demand as well as the stoichometry of electro-oxidation and reforming processes. Feedback part performs corrections of the controlled system output by additional manipulation of system inputs. Based on relative gain analysis (RGA), it is found that two individual PI control loops turn out suitable enough to control the system. Parameters of the PI controllers are tuned on the basis of open-loop step response experiments by applying the Magnitude Optimum Multiple Integration method (MOMI). The proposed feedforward-feedback control is verified on the SOFC stack model over a one-day operation cycle using the standard load profile of residential houses. The main advantage of the proposed controller is its simple structure and easy tuning, which makes it feasible for practical implementation.
Vrecko, D., Dolanc, G., Dolenc, B., Vrancic, D., Pregelj, B., Marra, D., Sorrentino, M., Pianese, C., Pohjoranta, A., & Juricic, D. (2015). Feedforward-feedback control of a SOFC power system: A simulation study. ECS Transactions, 68(1), 3151-3163. https://doi.org/10.1149/06801.3151ecst