Electrochimica Acta, Vol.177, 237-249, 2015
Control strategy power management, efficiency-optimization and operating-safety of a 5-kW solid oxide fuel cell system
The slow power tracking, operating safety, especially the fuel exhaustion, and high efficiency considerations are the key issues for integrated solid oxide fuel cell (SOFC) systems during power step up transients, resulting in the relatively poor dynamic capabilities and make the transient load following very challenging and must be enhanced. To this end, this paper first focus on addressing the efficiency optimization associated with simultaneous power and thermal management of a 5-kW SOFC system. Particularly, a traverse optimization process including cubic convolution interpolation algorithm are proposed to obtain optimal operating points (OOPs) with the maximum efficiency. Then this paper investigate the current implications on system step-up transient performance, then a two stage preconditioning current strategy and a feedback power reference control scheme is proposed for load stepup transients to balance fast load following and fuel starvation, after that safe thermal transient is validated. Simulation results show the efficacy of the control design by demonstrating the fast load following ability while maintaining the safe operation, thus safe; efficient and fast load transition can be achieved. (C) 2015 Elsevier Ltd. All rights reserved.
Keywords:Solid oxide fuel cell(SOFC);Optimal operating points(OOPs);pre-conditioning current strategy;feedback power reference control scheme;load step-up transients