Análise de funções de alívio para estimação de carregamentos após chaveamentos corretivos

Abstract

There are several studies proposing Corrective Switching technique for eliminating overloads in transmission branches. Some proposed Corrective Switching algorithms are based on electrical circuits theory or Relief Function methodology. This work presents a new methodology, determined analytically and based on a Two-ports network model, which estimates the loading of a branch in a linear way. The results obtained from this Relief Function, applied to Corrective Switching technique in contingency cases, are compared with the results of other methodologies previously developed and with the exact load flow tests in transmission systems. When carrying out the studies throughout this thesis, contingencies were created from line disconnections in the studied transmission systems - this alteration occasionally caused multiple branch overloads in the electric network, but they were analyzed one at a time. Another step is to verify the nonlinearities of the switching measures: to analyze if the electric quantities obtained from the application of a linear technique can present great variations with respect to the obtaining from a nonlinear model, meaning, an exact load flow, and to comprehend the influence that certain parameters present in the estimated loadings can exert on the non-linearity of these operation maneuvers. It is important to emphasize that the new network topology can be identified quickly, since the calculations necessary to estimate the new load are linear, which requires little computational effort. This enables an on-line application to find a feasible solution in Energy Management Centers.