Aspectos práticos e teóricos na análise de estabilidade de tensão

Abstract

This document concerns about the voltage stability phenomenon, which have been a growing interesting issue during the last years. Economics and ecological restrictions are causing an operation of several electrical systems under hard conditions, leading to several incidents around the world and problem over the voltage stability. The motivation behind this study comes from the adoption of a politic of cutoff load in São Paulo Area, as a result a raise load margin to the electrical power system. The proposal consists in compare the politic used by the companies in the electric sector of São Paulo Area to manual load cutoff in a necessity situation, with the tangent vector techniques. The tangent vector indicate the critical bus from the system where is used the same amount of cutoff load, with the purpose to compare with the politic used by these companies. In the second step additional shunt compensation will be adopted and the behavior of the load margin of the system will be checked, when this compensation is done in the group of critical bus or in the critical bus suggested by the companies. Another issue included here is basically theoretical which the motivation is to find an eigenvalue that is connected to the critical bus e indicate the behavior of that, when the load of system is increased, considering the reactive power limits of the generators.