Solid oxide fuel cell (SOFC) technology has the advantages of high efficiency, low emission and fuel flexibility, but high cost and short lifetime are still the bottlenecks hindering its large-scale commercial application. The performance of SOFC systems will gradually evolve into faults in the long run, leading to variation of the dynamic and static characteristics of the system. The control system designed according to the original system characteristic would face with problems such as parameter mismatch, inaccurate control and even wrong control laws. In this paper, based on a 1kW steam-reforming SOFC system multi-mode model, the dynamic and static characteristics of SOFC systems under the condition of performance degradation and fault evolution are investigated, and a complete health evaluation system is developed for the first time in the SOFC field to optimize the system control and identify early faults for the pre-treatment. The simulation results show that with the improved system controller higher system efficiency and longer lifetime of the SOFC system could be achieved, dealing with the performance degradation and fault evolution mechanisms in reality.
Keywords SOFC system, performance degradation, fault evolution, multi-mode model, health evaluation system, control optimization