考虑元件温-湿关联影响的氢燃料电池系统动态可靠性分析

Dynamic Reliability Analysis of Hydrogen Fuel Cell System Considering Influence of Element Temperature-humidity Correlation

为了研究元件关联作用对氢燃料电池系统可靠性的影响,以集流板、扩散层和催化层的性能状态与质子膜温度失效和湿度失效的关联关系为研究对象,利用马尔科夫方法建立元件多状态退化模型。通过转移系数描述元件状态转移率与关联特性的动态关系,构建新的状态转移矩阵;基于通用发生函数导出关联系统多态可靠性分析模型,并讨论了多元件关联情形的模型特点;结合Kolmogorov方程求得多态元件各状态下的概率,分别研究了单一关联组和多关联组温-湿复合影响两种情况下的系统可靠性趋势。结果表明:质子膜的状态转移率会随着集流板、扩散层和催化层性能的退化而改变;当上述元件处于高性能状态时,质子膜的关联特性使系统的可靠度更高,而这些元件在低性能状态时,关联特性使系统的可靠度更低;冷却元件的状态对系统可靠性的影响比增湿元件状态的影响大。研究结果可为电池系统可靠性设计和寿命周期预测提供理论依据。

To analyze the influence of element correlation on the reliability of a hydrogen fuel cell system,the correlation relationship among the performance states of the collector plate,diffusion layer,catalytic layer and the temperature and humidity failures of proton membrane is taken as the research object,and the elements’multi-state degradation model is established using the Markov method.A new state transition matrix is constructed by describing the dynamic relationship between the state transition rate and the associated characteristics of elements by the transition coefficient.Based on the universal generating function,the multi-state reliability analysis model of the associated system is derived,and its multi-element correlation characteristics are discussed.Combined with the Kolmogorov equation,the probability of each state of the multi-state element is obtained,and the reliability trends of battery system under the single correlated group and combined influence of temperature-humidity of multiple correlated groups are studied,respectively.Results show that the state transition rate of proton membrane changes with the performance degradation of the collector plate,diffusion layer and catalytic layer.When these elements are in a high-performance state,the correlation property of proton membrane makes the system more reliable.In comparison,the correlation property makes the system less reliable when these elements are in a low-performance state.The state of the cooling element has a greater influence on the system reliability than that of the humidifying element.The research results can provide a theoretical basis for the reliability design and life cycle prediction of the battery system.