Controlling Transient Behavior of Solid Oxide Fuel Cells Using an Invariant Property

该奖项的研究目标是解决提高SOFC的负荷跟踪能力和同时在剧烈功率波动下保持安全的暂态运行这一重要而又相互冲突的目标。负载跟随能力不足归因于运输延误，使SOFC在瞬变过程中容易出现氢气匮乏。氢饥饿将通过将燃料利用率限制在最佳范围内来解决，燃料利用率是SOFC的一个关键性能变量。由于复杂且昂贵的传感要求，直接测量燃料利用率的瞬时控制是不切实际的。相反，所提出的方法将通过使用不变性质来实现这一目标。它对压力、温度和内外重整反应的不变性，允许实现简单的控制。这项研究将揭示这一性质存在的潜在条件，并开发一种形式方法，以独立于模型的方式推导它。通过将这一特性融入含储能元件的混合SOFC系统的鲁棒控制策略中，在实现上述暂态控制的同时，将提高SOFC的负载跟踪能力。如果研究成功，SOFC的可用性将从均匀功率应用扩展到快速响应场景。它将提供可接受的瞬时响应，并减少感知和对系统动力学的有限知识，系统动力学由许多相互关联的物理现象组成。这项研究将为SOFC开辟一种适用于燃料类型、重整类型、电堆技术等各种变化的通用暂态控制方法的可能性。它将降低对传统方法中至关重要的模型识别和调整工作的需求。这项研究将包括来自多个工程学科的研究生和本科生，通过研究生研究、合作机会等，并将试图增加女性和少数族裔学生的参与。研究成果将通过大学和全系的外联活动以及通过出版物和参加会议来传播。

The research objective of this award is to address the important yet conflicting goals of improving load-following ability of SOFCs and simultaneously maintaining safe transient operation under aggressive power fluctuations. Deficient load-following is attributed to transport delays that render SOFCs susceptible to hydrogen starvation during transients. Hydrogen starvation will be addressed by limiting fuel utilization, a critical performance variable in SOFCs, within an optimal range. Transient control through direct measurement of fuel utilization is impractical due to elaborate and costly sensing requirement. In contrast, the proposed approach will achieve this objective by using an invariant property. Its invariance with respect to pressures, temperatures, and internal and external reforming reactions, admits simple control implementation. The research will reveal the underlying conditions for existence of this property and develop a formal approach for deriving it in a model independent manner. By integrating the property within robust control strategies for hybrid SOFC systems containing an energy storage element, it will improve the load-following ability of SOFCs while achieving the aforementioned transient control.If successful, this research will extend the usability of SOFCs from uniform power applications to rapid response scenarios. It will provide acceptable transient response with reduced sensing and limited knowledge of the system dynamics, which consists of numerous interconnected physical phenomena. The research will open the possibility of a generalized transient control approach for SOFCs that is applicable across variations in fuel types, reformer types, stack technologies, etc. It will lower the need for model identification and tuning efforts that are crucial in traditional approaches. The research will involve graduate and undergraduate students from multiple engineering disciplines through graduate research, co-op opportunities, etc. and will attempt to increase the involvement of women and minority students. Research results will be disseminated through university and department-wide outreach activities, and through publications and conference participation.