Analysis of relief functions to estimate branch loadings after Corrective Switchings
Corrective Switching, Loading Estimate, Relief Functions, Linear Methodology, Two-ports Network Equivalent.
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 linear methodology that proposes to compare the results obtained from the execution of a Relief Function applied to Corrective Switching technique in contingency cases with the results of other methodologies previously developed and with the load flow tests in transmission systems. This Relief Function has been determined analytically and it is based on a Two-ports network model. 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 nonlinearity 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.