An approach for preventing system insecurities arising from line and transformer outages

Abstract

This paper presents an algorithm that improves steady state security of a power system. An objective function which includes power flows in the overloaded system elements and bus voltages that exceed the permissible limits is formulated. Weighting factors, obtained from the magnitudes and frequencies of the violations, are also used in this function. An optimal combination of controlling variables, such as voltage magnitudes at generator buses, real power generation, transformer and phase shifter tap settings, is determined by minimizing the objective function. Instead of the non-linear load flow equations, sensitivity analysis approach has been used to reduce computation time and effort. This technique has been applied to a 6 bus model and a 26 bus version of the Saskatchewan Power Corporation transmission system; and some of the more interesting results are presented.