Effect of the Operating Strategy of a Solid Oxide Fuel Cell on the Effectiveness of Decentralized Linear Controllers

The effect of the operating strategy of the solid oxide fuel cell (SOFC) on the applicability of decentralized controllers is investigated in this work using a zero-dimensional model. Using frequency dependent interaction measures, three different operating modes resulting in 18 control structures are analyzed at different operating points. The results indicate that only 5 out of the 18 control structures are suitable for decentralized controller design. This is confirmed from the closed loop simulations using proportional, integral, and derivative (PID) controllers for the loops which are tuned sequentially. It is also shown through simulations that multivariable controllers such as decoupling controllers and model predictive controllers will be applicable for the remaining control structures with strong interactions. The results of this work will be useful in the design of plantwide controllers for the SOFC system.