除氧器故障诊断的含未测节点的符号有向图方法

Algorithms of SDG-based Fault Diagnosis with Unmeasured Nodes for Deaerator

符号有向图(SDG)模型已被用于系统运行操作的故障诊断,系统图模型中节点表示部件,边表示故障传播特征,主要分析已知报警集合寻找潜在故障源的问题。工业过程中许多过程状态不能测量或不能在线测量,使得原相容性故障传播通道失效。针对SDG模型中的部分节点因未测量造成的信息缺失,给出含未测节点的SDG模型的数学表达;并通过对路径函数和节点函数的转化,结合有向图(DG)的可达性理论,给出了两种转化故障诊断方法:完全转换的含未测节点严格符号有向图方法和部分转换的含未测节点严格符号有向图方法。算例研究表明,该方法具有较强的故障诊断能力。

The fault diagnosis algorithm using SDG （signed directed graph） as a model of the system is useful to operative diagnosis of fault which occurred in processes. Graph-based systems are models wherein the nodes represent the components and the edges represent the fault propagation between the components, This paper considers the problem of identifying the nodes that are potential sources for causing a given set of alarms to ring alarms. For process industries, however, all the process nodes are not usually measured and the consistent fault propagation path assumption is unavailable. Focus on the SDG- based systems where some nodes are not online observed in this paper, we present the SDG model for the systems and two fault diagnosis algorithms （SDGC and SDGP） through the transformation of edge and node function fusing the reachability theory. The case studies show the algorithm has better resolution in fault diagnosis online.