A New Algorithm for Enumeration of Minimum Cutsets of Graph by Branch Addition

Nowadays, reliability is one of the most important studies of power systems. There are different methods to enumerate power system´s reliability indices such as series-parallel simplification, minimum path and minimum cutset. When the network has a simple reliability block diagram and this block consists of only series and/or parallel elements, it can be easily found the link between input nodes and output nodes and reliability indices calculation is very easy. However, in complex reliability block diagram, series-parallel simplification cannot be used and other algorithms should be searched in such cases. Some of these algorithms, which are based on finding minimum paths, need a large size of memory and more computation time. Thus, these algorithms are also not useful in complex systems. In this paper, a new minimum cutset enumeration algorithm is presented, that can be a suitable method in such systems. Several methods have been proposed to minimum cutests enumeration in journals and literatures. In this paper, a suitable algorithm that is not sensitive to number of input nodes of graph will be introduced. Calculation of all order of minimum cutsets of a given graph in a simple way is another advantage of the proposed method. The novel algorithm takes less time to calculate minimum cutsets, compared with others. As a case study, this algorithm is applied to the IEEE 7 bus test network and also to a part of Iran transmission and subtransmission system (Khorasan regional network)