A feedback based load shaping strategy for fuel utilization control in SOFC systems

Solid oxide fuel cells are attractive energy conversion devices due to their fuel flexibility and high efficiency. Fuel utilization is a critical variable in SOFC systems that directly impacts efficiency and longevity. In this paper we propose a control strategy for mitigating drastic fluctuations in fuel utilization that arise during load transients. The strategy uses a feedback based dynamic input shaping approach. A preliminary control law derived from a model-based analysis forms the basis of this design. The strategy requires one fuel flow sensor upstream of the integrated fuel processor and admits convenient integration into a comprehensive hybrid fuel cell control algorithm.