engleski

Contingency Selection Algorithms for Transmission Line Overload Analysis in On-line Security Assessment

The purpose of steady-state power system security analysis is to identify most of contingencies which cause component limit violations (in this paper overloads) and to predict severity of any such violation in very short period of time. For large systems, even if only single component contingencies are considered, and even if fast solution methods are employed, full AC analysis of all cases can be prohibitively time consuming, especially in on-line mode. In order to avoid this computational burden, contingency list is formed by approximate load flow methods which in contingency selection procedure estimate in advance contingencies more likely to cause limit violations, followed by full AC analysis only for the most severe cases. Contingency selection procedure is automated using ranking methods according to performance index values. These methods are enhanced by using sparse matrix techniques and local solution concept involving external equivalents in field of avoiding time consuming routines and reducing whole problem. The paper tends to contribute with current literature survey and presentation of results obtained by testing several contingency selection algorithms on 24-bus and 114-bus hypothetical parts of Croatia's power system. The outages causing overloads are concerned in order to examine efficiences of the algorithms through capture rates and to determine their on-line applicabilities in modern power system control centres.

line overload ; contingency selection ; security analysis

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