Performance Degradation and Fault Mechanisms Based Solid Oxide Fuel Cell System Multimode Modeling and Analysis

Abstract

Solid oxide fuel cell (SOFC) system becomes one of the most promising power generation devices for its high efficiency and low emission. However, the commercialization process of SOFC is restricted due to the problems of life-span and cost, so the performance degradation and fault mechanisms of SOFC systems are partially studied by some scholars. An SOFC system model that efficiently describes system performance degradation and various faults characteristics during long term operation plays pivotal role in improving system performance and extending life time. In this paper, a high fidelity steam-reforming SOFC system model incorporating system performance degradation principles and faults evolving mechanisms is developed based on physical laws and validated with experimental data. With this model the drifting of static optimal operation point (OOP) caused by performance degradation and different fault combinations, together with system input sensitivity analysis are investigated. The results indicate that the introduction of the degradation and fault mechanisms would increase the accuracy of the system model, and decrease system electrical efficiency. The steam-reforming SOFC system has a higher sensitivity to the stack fault than to the reformer fault.