抄録
The purpose of this paper is to present a fault location method for a large scale plant.
Operators in a control room should take measures to meet the situation for maintenance of the plant function when a detector informs them of something wrong. On the other hand, the matter of plant is often detected at failure propagated devices rather than at the failed device (failure origin). In addition, the number of detectors which inform them of something wrong increases exponentially. Therefore, because they can not locate the failure origin in a short time, they can not take corrective counter operations.
Fault location we propose is executed in the following procedure. First, a digraph which shows the failure propagation network of the plant is constructed from devices of the plant or failure modes of devices (nodes) and failure propagation relations between nodes (branches). Second, some candidates for the failure origin are selected in the digraph by back-tracing on branches starting from the failure propagated nodes. Third, the candidates are screened by back-tracing starting from normal state nodes, failure propagation probabilities and failure propagation time between adjacent nodes. Fourth, the failure propagation probabilities and the failure rates of the devices are used to evaluate the priority ranking among the screened candidates.
The method makes it easy to find out the failure origin and to take proper counter operations when the detector informs operators of something wrong.
