Análise da eficácia de indicadores de proximidade de colapso de tensão através de um programa de estabilidade

Abstract

In the last years, it has been observed that the amoun of investment to improve and increase the power system generation and transmission has not matched the growing load demand. As a result, the system has been working more loaded and, therefore, nearer to its limits. These facts have put in evidence the problem of insufficient reserve of reactive supply which is necessary to support the system voltage levei as the load increase. In this situation, a lack of reactive power may lead one or more system load busses to the well known voltage collapse phenomenon. Having this in mind, this work aims to study the developing of the voltage collapse and evaluate some sensitivity coefficients proposed to indicate the occurrence of such phenomenon. To accomplish this objective, it is used a modifíed dynamic stability analysis program in which three voltage collapse proximity indicators (VCPI’s) are implemented. Using static and dynamic load models, several studies are then conducted in order to show the voltage collapse mechanism and the behavior of the sensitivity coefficients implemented. The simulations take into account the effect of limited generator reactive power supply. Two test systems are investigated: a small 3-bus test system, which facilitates the conclusions, and also a 36-bus system.