Detekcija i otklanjanje uzroka nestabilnog rada sistema

Abstract

Small-signal stability, which is also called static stability or modal analysis, deals with system stability in case of small disturbances such as consumption and production variations on hourly and daily basis. Advantage of this type of analysis is its global character because it provides all system state matrix eigenvalues, i.e. system poles, within single system calculation. Existence of single system pole with positive real part indicates unstable system. Measure of relative participation of a particular state variable, which is correlated to particular generator, and particular system pole is provided by calculating participation factors. Sorting of participation factors for all system poles in descending order and establishing a correlation to certain state variable of particular generator provides feedback to generators that are dominant causes of existence of system poles with positive real part. The paper presents calculation of system eigenvalues and establishment of user feedback to generator causing appearance of unstable pole. The establishment of this feedback and elimination of unstable system pole by changing generator parameters is demonstrated on the example of the real distribution system of Leskovac branch with over 2500 nodes and more than 40 synchronous generators connected.