A systematic approach for calculating reliability of substation automation system functions

The substation automation system performs monitoring, controlling and protection functions in an electric switchyard facility. The functions have high reliability requirements. Consequently, the reliability of the functions must be evaluated during the design of a substation automation system. This paper presents a systematic approach for calculating the reliability and availability of substation functions which have multiple sources and multiple terminals that are connected by redundant paths and whose dependency is expressed by AND and OR Boolean constructs.