Improvement of Optimal Power Flow and System Security Using Fuzzy Based Contingency Ranking

To maintain security of a large power system, it is desirable to estimate the effect of contingencies and plan suitable steps to improve system security. Contingency screening and ranking is one of the important components of on-line system security improvement. The objective of contingency screening and ranking is to quickly and accurately select a shortlist of critical contingencies from a large list of potential contingencies and rank them according to their severity. The ranking is evaluated using compound rule based fuzzy logic controller for eliminating masking effect.