Reliability Assessment of Protection System for Switchyard Using Fault-Tree Analysis

The purpose of this paper is assessing the reliability of the protection system for a switchyard by fault-tree analysis. Through the fault-tree analysis, one may understand the reliability of the protection system and may obtain the importance of elements influencing reliability by risk reduction worth as well as know where the weakness of the protection system is. Compared with traditional methods (e.g., Markov model and Monte Carlo simulation), the fault-tree analysis requires less computation and includes crisp cause-effect relation. In this paper, a 345 kV switchyard in the 3^rd nuclear power plant in Taiwan serves as an example for illustrating the results of the proposed method. From the test result, it was found that the fault-tree analysis can efficiently help power engineers assess the reliability of the protection system.