Survey on H∞ Robust Control of the Solid Oxide Fuel Cell

Excessive use of fuel or being underutilized will make the actual performance of solid oxide fuel cells (SOFCs) affected by a lot, and at the same time, in order to meet the demands of DC load voltage, a controller of the SOFC that is subjected to small varying loads is proposed on the basis of H∞ control theory. For the controller design, a state-space representation of the SOFC by using small-signal linearization is derived. To evaluate the control performance, the presented H∞ controller is tested on the SOFC stack with various load disturbances. The results show that the obtained H∞ controller can mitigate the voltage oscillations and deviations and can keep fuel utilization constant at varying loads.