Abedi - Amirkabir University & EPRC I.R. Iran
Barahmandpoor - Amirkabir University & EPRC I.R. Iran

In this paper an attempt has been made to extend present available techniques to evaluate contingency selection (ranking) in Iranian 230 and 400 KV national grid. The results rank the transmission line and transformer outages which cause the most severe overloads and voltage drops in Iran’s national interconnected power system.