A Direct Method to Calculate the Frequency and Duration of Failures for Large Networks

This paper presents a method to find the frequency and duration of outage of large complex networks through the network approach. Unreliable nodes can be considered. Numerical examples are given to elucidate the theory. The results from this technique are fairly accurate. A feature of the method is that it can handle large systems having reliable nodes with a present day computer. Even for those systems which contain unreliable nodes, the number of combinations of unreliable nodes required is much less than the number of terms needed by any path or cutset enumeration method. The use of delta-star transformations introduces some error in the results, but the error is small enough as seen from the numerical values for the examples solved in this paper.