大规模储能中混合型超级电容器单体失效特征参数研究

Supercapacitor is a new kind of energy storage device with promising prospects in the application of large-scale energy storage area. At present, the research of supercapacitor mainly focuses on material and the preparation process, but the basic research of its use in the field of large-scale energy storage is yet extremely limited. Owing to the low terminal voltage of a supercapacitor monomer, it needs large numbers of monomers in series to fulfil the voltage level requirement of energy storage system. The failure of one single cell will bring about an entire collapse of the module or even the whole energy storage system. This research will be of great significance of supercapacitors in the large-scale energy storage areas. The subject intends to study the failure characteristics of hybrid supercapacitor monomer, using methods of system identification to establish the mathematical model on the basis of analysis in the hybrid supercapacitor mechanism, reveals the failure law of hybrid supercapacitor monomer under a variety of working conditions, and develops the diagnostic methods as well as failure criteria. The achievements will develop a set of identification and diagnosis algorithm of failure characteristic parameters with high accuracy and rapid response for hybrid supercapacitor, which is critical for further development of intelligent supercapacitor management system with the function of failure judgment and warning mechanism. The research will also establish a foundation for reliable utilization of hybrid supercapacitors in large-scale energy storage application.

超级电容器是近年来迅速发展的适合于大规模储能应用的新型储能器件。目前针对超级电容器的研究热点多集中在器件材料和制备方法上，而在大规模储能应用中的基础研究相对缺乏。超级电容器单体电压较低，需要大量串联来满足储能系统的电压等级要求，若其中一个单体失效，将导致模块甚至整个储能系统无法正常工作。本课题拟对混合型超级电容器单体失效特征进行深入探讨，在对混合型超级电容器机理分析的基础上采用系统辨识的方法建立数学模型，揭示混合型超级电容器单体在各种工况下的失效特征和参数变化规律，研究失效状态诊断方法和失效判据，这对超级电容器在大规模储能领域的应用有重要意义。本课题成果将构建一套适用于混合型超级电容器的实时性好、准确性高的单体失效特征参数辨识与诊断方法，为进一步开发具有失效判断和预警机制的超级电容器智能管理系统，实现混合型超级电容器的大规模可靠使用打下基础。

结合大规模储能模块应用背景，针对性地设计了研究混合型超级电容器电气性能的直流综合特性测试方案。提出了一种一阶等效改进模型，通过电路分析论证了模型结构的有效性。使用差分进化算法辨识模型参数，试验结果表明该模型能较准确地表征混合型超级电容器的非线性充放电特性，有利于单体特征参数的多工况变化规律研究与模块不一致性仿真分析。研究了超级电容器的老化因素与耗尽失效特征，在理论分析的基础上，选用已商业化的超级电容器模块完成不同工况条件的特性测试，试验结果体现了超级电容器的模型参数、脉冲功率、可用能量等特征参数与老化应力因素的强相关性。基于综合特性测试方案的大量非额定工况测试数据，研究了当前寿命状态下不同工况的混合型超级电容器电气性能。以等效改进模型参数与自放电剩余电压为例，通过回归统计方式建立全工况范围的多因素归算模型。采用基于支持向量机的方法研究小样本情况下的模型参数预测。研究了大规模储能中，超级电容器的不一致性问题，提出了多项量化储能器件不一致性的评价指标。提出了与大数据技术相结合的下一代超级电容器智能管理系统方案。