Desenvolvimento de índices baseados em equivalentes de Thévenin para avaliação de segurança de tensão de sistemas elétricos de potência

Abstract

In this work are proposed two efficient indexes based on Thévenin equivalent for assessment of voltage safety of large Electric Power Systems. These indexes are called Voltage Stability Index and Voltage Control Loss Index and are based on the characteristic of maximum power transfer of linear electrical circuits. In this sense, we propose a new methodology to estimate the Thévenin impedance based on the Sensitivity Analysis technique of the Jacobian matrix of power flow problem. The Voltage Stability Index proposed can be calculated for all system buses at a given operating point, providing a quick estimate of the computational point of view of the Loading Margin and an indication of the critical buses of the system. On the other hand, the Voltage Control Loss Index is calculated only for the PV type buses and provides an indication of the critical generators for control of voltage of the region in analisys. The proposed indexes are evaluated by studying tutorials systems, medium size systems and a large system based on the brazilian National Interconnected System. Whenever possible looking up validate the results obtained through comparisons with the techniques of the tangent vector of the Continuation Method and of the smaller Reactive Power Margin of the V-Q curves, which already are established techniques of voltage stability analysis of Electric Power Systems.